How to find research summary in physics - ACT Science
Card 0 of 464
A physicist performs a series of experiments to determine the relative magnitude of electric charge on four particles. A given particle is considered to have a higher magnitude of charge than another if it will push out (or draw in) a positive test charge farther than the other particle.
A particle that pushes the test charge has positive charge, while a particle that pulls (or draws in) the test charge has negative charge. This is known as the sign of the charge. Magnitude of charge is unrelated to sign.
The experiment is conducted on a horizontal axis that measures from 20m in total: from –10m on the left to +10m on the right, with a measurement of 0m in the middle.
Experiment 1
Particle A is placed at position –5m on the horizontal axis. The test charge has a specific magnitude of charge and is located at +3m on that same axis. The result of the experiment is that the test charge is displaced to +7.5m.
Experiment 2
Particle B is placed at position –8m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at 0m on that same axis. The result of the experiment is that the test charge is displaced to –7.5m.
Experiment 3
Particle C is placed at position 0m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at +8m on that same axis. The result of the experiment is that the test charge is displaced to +10m.
Experiment 4
Particle D is placed at position –5.5m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at +2.5m on that same axis. The result of the experiment is that the test charge is displaced to +7.5m.
It can be inferred from the experiment that __________.
A physicist performs a series of experiments to determine the relative magnitude of electric charge on four particles. A given particle is considered to have a higher magnitude of charge than another if it will push out (or draw in) a positive test charge farther than the other particle.
A particle that pushes the test charge has positive charge, while a particle that pulls (or draws in) the test charge has negative charge. This is known as the sign of the charge. Magnitude of charge is unrelated to sign.
The experiment is conducted on a horizontal axis that measures from 20m in total: from –10m on the left to +10m on the right, with a measurement of 0m in the middle.
Experiment 1
Particle A is placed at position –5m on the horizontal axis. The test charge has a specific magnitude of charge and is located at +3m on that same axis. The result of the experiment is that the test charge is displaced to +7.5m.
Experiment 2
Particle B is placed at position –8m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at 0m on that same axis. The result of the experiment is that the test charge is displaced to –7.5m.
Experiment 3
Particle C is placed at position 0m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at +8m on that same axis. The result of the experiment is that the test charge is displaced to +10m.
Experiment 4
Particle D is placed at position –5.5m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at +2.5m on that same axis. The result of the experiment is that the test charge is displaced to +7.5m.
It can be inferred from the experiment that __________.
Subtract the position of the particle from the initial position of the test charge.
In each experiment the result is 8m.
Subtract the position of the particle from the initial position of the test charge.
In each experiment the result is 8m.
Compare your answer with the correct one above
A physicist performs a series of experiments to determine the relative magnitude of electric charge on four particles. A given particle is considered to have a higher magnitude of charge than another if it will push out (or draw in) a positive test charge farther than the other particle.
A particle that pushes the test charge has positive charge, while a particle that pulls (or draws in) the test charge has negative charge. This is known as the sign of the charge. Magnitude of charge is unrelated to sign.
The experiment is conducted on a horizontal axis that measures from 20m in total: from –10m on the left to +10m on the right, with a measurement of 0m in the middle.
Experiment 1
Particle A is placed at position –5m on the horizontal axis. The test charge has a specific magnitude of charge and is located at +3m on that same axis. The result of the experiment is that the test charge is displaced to +7.5m.
Experiment 2
Particle B is placed at position –8m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at 0m on that same axis. The result of the experiment is that the test charge is displaced to –7.5m.
Experiment 3
Particle C is placed at position 0m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at +8m on that same axis. The result of the experiment is that the test charge is displaced to +10m.
Experiment 4
Particle D is placed at position –5.5m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at +2.5m on that same axis. The result of the experiment is that the test charge is displaced to +7.5m.
The results of Experiment 1 and 2 show that __________.
A physicist performs a series of experiments to determine the relative magnitude of electric charge on four particles. A given particle is considered to have a higher magnitude of charge than another if it will push out (or draw in) a positive test charge farther than the other particle.
A particle that pushes the test charge has positive charge, while a particle that pulls (or draws in) the test charge has negative charge. This is known as the sign of the charge. Magnitude of charge is unrelated to sign.
The experiment is conducted on a horizontal axis that measures from 20m in total: from –10m on the left to +10m on the right, with a measurement of 0m in the middle.
Experiment 1
Particle A is placed at position –5m on the horizontal axis. The test charge has a specific magnitude of charge and is located at +3m on that same axis. The result of the experiment is that the test charge is displaced to +7.5m.
Experiment 2
Particle B is placed at position –8m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at 0m on that same axis. The result of the experiment is that the test charge is displaced to –7.5m.
Experiment 3
Particle C is placed at position 0m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at +8m on that same axis. The result of the experiment is that the test charge is displaced to +10m.
Experiment 4
Particle D is placed at position –5.5m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at +2.5m on that same axis. The result of the experiment is that the test charge is displaced to +7.5m.
The results of Experiment 1 and 2 show that __________.
Particle A has a lower magnitude of charge than particle B because it displaced the test charge by a smaller amount.
In experiment 1, the test charge moved from +3m to +7.5m, a difference of 4.5m.
In experiment 2, the test charge moved from 0m to –7.5m, a difference of 7.5m.
The experiments give no insight into charge density.
Particle A has a lower magnitude of charge than particle B because it displaced the test charge by a smaller amount.
In experiment 1, the test charge moved from +3m to +7.5m, a difference of 4.5m.
In experiment 2, the test charge moved from 0m to –7.5m, a difference of 7.5m.
The experiments give no insight into charge density.
Compare your answer with the correct one above
A physicist performs a series of experiments to determine the relative magnitude of electric charge on four particles. A given particle is considered to have a higher magnitude of charge than another if it will push out (or draw in) a positive test charge farther than the other particle.
A particle that pushes the test charge has positive charge, while a particle that pulls (or draws in) the test charge has negative charge. This is known as the sign of the charge. Magnitude of charge is unrelated to sign.
The experiment is conducted on a horizontal axis that measures from 20m in total: from –10m on the left to +10m on the right, with a measurement of 0m in the middle.
Experiment 1
Particle A is placed at position –5m on the horizontal axis. The test charge has a specific magnitude of charge and is located at +3m on that same axis. The result of the experiment is that the test charge is displaced to +7.5m.
Experiment 2
Particle B is placed at position –8m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at 0m on that same axis. The result of the experiment is that the test charge is displaced to –7.5m.
Experiment 3
Particle C is placed at position 0m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at +8m on that same axis. The result of the experiment is that the test charge is displaced to +10m.
Experiment 4
Particle D is placed at position –5.5m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at +2.5m on that same axis. The result of the experiment is that the test charge is displaced to +7.5m.
Which of the particles is negatively charged?
A physicist performs a series of experiments to determine the relative magnitude of electric charge on four particles. A given particle is considered to have a higher magnitude of charge than another if it will push out (or draw in) a positive test charge farther than the other particle.
A particle that pushes the test charge has positive charge, while a particle that pulls (or draws in) the test charge has negative charge. This is known as the sign of the charge. Magnitude of charge is unrelated to sign.
The experiment is conducted on a horizontal axis that measures from 20m in total: from –10m on the left to +10m on the right, with a measurement of 0m in the middle.
Experiment 1
Particle A is placed at position –5m on the horizontal axis. The test charge has a specific magnitude of charge and is located at +3m on that same axis. The result of the experiment is that the test charge is displaced to +7.5m.
Experiment 2
Particle B is placed at position –8m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at 0m on that same axis. The result of the experiment is that the test charge is displaced to –7.5m.
Experiment 3
Particle C is placed at position 0m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at +8m on that same axis. The result of the experiment is that the test charge is displaced to +10m.
Experiment 4
Particle D is placed at position –5.5m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at +2.5m on that same axis. The result of the experiment is that the test charge is displaced to +7.5m.
Which of the particles is negatively charged?
All of the particles are initially placed to the left of the test charge. Particle B is the only one that "draws in" the test charge to the left, from 0m to –7.5m (we are told initially that the axis runs from –10m on the left to 10m on the right, with 0m in the middle).
All of the particles are initially placed to the left of the test charge. Particle B is the only one that "draws in" the test charge to the left, from 0m to –7.5m (we are told initially that the axis runs from –10m on the left to 10m on the right, with 0m in the middle).
Compare your answer with the correct one above
A physicist performs a series of experiments to determine the relative magnitude of electric charge on four particles. A given particle is considered to have a higher magnitude of charge than another if it will push out (or draw in) a positive test charge farther than the other particle.
A particle that pushes the test charge has positive charge, while a particle that pulls (or draws in) the test charge has negative charge. This is known as the sign of the charge. Magnitude of charge is unrelated to sign.
The experiment is conducted on a horizontal axis that measures from 20m in total: from –10m on the left to +10m on the right, with a measurement of 0m in the middle.
Experiment 1
Particle A is placed at position –5m on the horizontal axis. The test charge has a specific magnitude of charge and is located at +3m on that same axis. The result of the experiment is that the test charge is displaced to +7.5m.
Experiment 2
Particle B is placed at position –8m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at 0m on that same axis. The result of the experiment is that the test charge is displaced to –7.5m.
Experiment 3
Particle C is placed at position 0m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at +8m on that same axis. The result of the experiment is that the test charge is displaced to +10m.
Experiment 4
Particle D is placed at position –5.5m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at +2.5m on that same axis. The result of the experiment is that the test charge is displaced to +7.5m.
If particle C and particle D are placed on the axis at the same time, accoring to the results of the experiment, what is likely to occur?
A physicist performs a series of experiments to determine the relative magnitude of electric charge on four particles. A given particle is considered to have a higher magnitude of charge than another if it will push out (or draw in) a positive test charge farther than the other particle.
A particle that pushes the test charge has positive charge, while a particle that pulls (or draws in) the test charge has negative charge. This is known as the sign of the charge. Magnitude of charge is unrelated to sign.
The experiment is conducted on a horizontal axis that measures from 20m in total: from –10m on the left to +10m on the right, with a measurement of 0m in the middle.
Experiment 1
Particle A is placed at position –5m on the horizontal axis. The test charge has a specific magnitude of charge and is located at +3m on that same axis. The result of the experiment is that the test charge is displaced to +7.5m.
Experiment 2
Particle B is placed at position –8m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at 0m on that same axis. The result of the experiment is that the test charge is displaced to –7.5m.
Experiment 3
Particle C is placed at position 0m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at +8m on that same axis. The result of the experiment is that the test charge is displaced to +10m.
Experiment 4
Particle D is placed at position –5.5m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at +2.5m on that same axis. The result of the experiment is that the test charge is displaced to +7.5m.
If particle C and particle D are placed on the axis at the same time, accoring to the results of the experiment, what is likely to occur?
The best answer is that they would push (repel) each other. We know from the effects of a positive particle on a positive test charge that like signs repel and unlike signs draw in (attract) each other.
We know the two particles have the same sign (possitive) because of how they affect the test charge in the experiments.
We cannot speculate about how the combined effect of their relative charges would displace a test charge without knowing their exact locations on the axis.
We know that there must be some reaction.
The best answer is that they would push (repel) each other. We know from the effects of a positive particle on a positive test charge that like signs repel and unlike signs draw in (attract) each other.
We know the two particles have the same sign (possitive) because of how they affect the test charge in the experiments.
We cannot speculate about how the combined effect of their relative charges would displace a test charge without knowing their exact locations on the axis.
We know that there must be some reaction.
Compare your answer with the correct one above
A physicist performs a series of experiments to determine the relative magnitude of electric charge on four particles. A given particle is considered to have a higher magnitude of charge than another if it will push out (or draw in) a positive test charge farther than the other particle.
A particle that pushes the test charge has positive charge, while a particle that pulls (or draws in) the test charge has negative charge. This is known as the sign of the charge. Magnitude of charge is unrelated to sign.
The experiment is conducted on a horizontal axis that measures from 20m in total: from –10m on the left to +10m on the right, with a measurement of 0m in the middle.
Experiment 1
Particle A is placed at position –5m on the horizontal axis. The test charge has a specific magnitude of charge and is located at +3m on that same axis. The result of the experiment is that the test charge is displaced to +7.5m.
Experiment 2
Particle B is placed at position –8m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at 0m on that same axis. The result of the experiment is that the test charge is displaced to –7.5m.
Experiment 3
Particle C is placed at position 0m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at +8m on that same axis. The result of the experiment is that the test charge is displaced to +10m.
Experiment 4
Particle D is placed at position –5.5m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at +2.5m on that same axis. The result of the experiment is that the test charge is displaced to +7.5m.
The results of experiments 3 and 4 show that __________.
A physicist performs a series of experiments to determine the relative magnitude of electric charge on four particles. A given particle is considered to have a higher magnitude of charge than another if it will push out (or draw in) a positive test charge farther than the other particle.
A particle that pushes the test charge has positive charge, while a particle that pulls (or draws in) the test charge has negative charge. This is known as the sign of the charge. Magnitude of charge is unrelated to sign.
The experiment is conducted on a horizontal axis that measures from 20m in total: from –10m on the left to +10m on the right, with a measurement of 0m in the middle.
Experiment 1
Particle A is placed at position –5m on the horizontal axis. The test charge has a specific magnitude of charge and is located at +3m on that same axis. The result of the experiment is that the test charge is displaced to +7.5m.
Experiment 2
Particle B is placed at position –8m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at 0m on that same axis. The result of the experiment is that the test charge is displaced to –7.5m.
Experiment 3
Particle C is placed at position 0m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at +8m on that same axis. The result of the experiment is that the test charge is displaced to +10m.
Experiment 4
Particle D is placed at position –5.5m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at +2.5m on that same axis. The result of the experiment is that the test charge is displaced to +7.5m.
The results of experiments 3 and 4 show that __________.
We know that particles D and C have the same sign, as they pushed the test charge in the same direction.
We know that D has the higher magnitude because it displaced the test charge from +2.5m to +7.5m, a difference of 5m, while C displaced the test charge from +8m to +10m, a difference of 2m.
We know that particles D and C have the same sign, as they pushed the test charge in the same direction.
We know that D has the higher magnitude because it displaced the test charge from +2.5m to +7.5m, a difference of 5m, while C displaced the test charge from +8m to +10m, a difference of 2m.
Compare your answer with the correct one above
A physicist performs a series of experiments to determine the relative magnitude of electric charge on four particles. A given particle is considered to have a higher magnitude of charge than another if it will push out (or draw in) a positive test charge farther than the other particle.
A particle that pushes the test charge has positive charge, while a particle that pulls (or draws in) the test charge has negative charge. This is known as the sign of the charge. Magnitude of charge is unrelated to sign.
The experiment is conducted on a horizontal axis that measures from 20m in total: from –10m on the left to +10m on the right, with a measurement of 0m in the middle.
Experiment 1
Particle A is placed at position –5m on the horizontal axis. The test charge has a specific magnitude of charge and is located at +3m on that same axis. The result of the experiment is that the test charge is displaced to +7.5m.
Experiment 2
Particle B is placed at position –8m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at 0m on that same axis. The result of the experiment is that the test charge is displaced to –7.5m.
Experiment 3
Particle C is placed at position 0m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at +8m on that same axis. The result of the experiment is that the test charge is displaced to +10m.
Experiment 4
Particle D is placed at position –5.5m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at +2.5m on that same axis. The result of the experiment is that the test charge is displaced to +7.5m.
Which of the following represents the order of charge of the four particles, from highest to lowest?
A physicist performs a series of experiments to determine the relative magnitude of electric charge on four particles. A given particle is considered to have a higher magnitude of charge than another if it will push out (or draw in) a positive test charge farther than the other particle.
A particle that pushes the test charge has positive charge, while a particle that pulls (or draws in) the test charge has negative charge. This is known as the sign of the charge. Magnitude of charge is unrelated to sign.
The experiment is conducted on a horizontal axis that measures from 20m in total: from –10m on the left to +10m on the right, with a measurement of 0m in the middle.
Experiment 1
Particle A is placed at position –5m on the horizontal axis. The test charge has a specific magnitude of charge and is located at +3m on that same axis. The result of the experiment is that the test charge is displaced to +7.5m.
Experiment 2
Particle B is placed at position –8m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at 0m on that same axis. The result of the experiment is that the test charge is displaced to –7.5m.
Experiment 3
Particle C is placed at position 0m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at +8m on that same axis. The result of the experiment is that the test charge is displaced to +10m.
Experiment 4
Particle D is placed at position –5.5m on the horizontal axis. The test charge has the same magnitude of charge as the previous experiment and is located at +2.5m on that same axis. The result of the experiment is that the test charge is displaced to +7.5m.
Which of the following represents the order of charge of the four particles, from highest to lowest?
Particle B displaced the test charge from 0m to –7.5m, a distance of 7.5m
Particle D displaced the test charge from +2.5m to +7.5m, a distance of 5m
Particle A displaced the test charge from +3m to +7.5m, a distance of 4.5m
Particle C displaced the test charge from +8m to +10m, a distance of 2m
Particle B displaced the test charge from 0m to –7.5m, a distance of 7.5m
Particle D displaced the test charge from +2.5m to +7.5m, a distance of 5m
Particle A displaced the test charge from +3m to +7.5m, a distance of 4.5m
Particle C displaced the test charge from +8m to +10m, a distance of 2m
Compare your answer with the correct one above
Metal wires are often used to conduct electricity. The electricity that flows through a wire is measured as "current." Therefore, a wire with an electric current is called a current carrying wire.
Current carrying wires also have a tendency to produce magnetic fields that circulate around them. The strength of that magnetic field is determined by the following equation where 
is the magnetic field strength (Teslas), 
is the electric current (Amps), 
is the distance (meters) of an object to the current carrying wire. 
is a constant.
If a wire has a magnetic field of 
at a distance of 1 meter, what would the magnetic field be at 4 meters?
Metal wires are often used to conduct electricity. The electricity that flows through a wire is measured as "current." Therefore, a wire with an electric current is called a current carrying wire.
Current carrying wires also have a tendency to produce magnetic fields that circulate around them. The strength of that magnetic field is determined by the following equation where
If a wire has a magnetic field of
The correct answer is 
. According to the passage, 
represents the distance to the current carrying wire. Since 
is in the denominator, we know that the magnetic field strength 
and the distance are inversely related. That is, 
(as 
goes up, 
goes proportionally down). Therefore, if we multiply the distance by four, we plug into our equation, ignoring all other parameters and get a magnetic field with one fourth of the original strength.
The correct answer is
Compare your answer with the correct one above
The photoelectric effect is a phenomenon that has led to many important scientific discoveries. Light of a particular wavelength is shined onto a piece of metal, showering the metal with photons. Wavelength is inversely related to a photon's energy. That is, with a smaller wavelength, the photon has greater energy. The wavelength of the light is decreased until a detector next to the metal senses that electrons are being ejected from the metal. This sensor also tells us how many electrons are ejected per second, which we call electrical current. At this point, any additional decrease in wavelength does not affect the number of electrons ejected. This point is called the metal's work function. However, if we then begin to increase the intensity of the light being shone (meaning the amount of light as opposed to the light's wavelength), the number of electrons picked up by the sensor increases.
Based on the information in the passage, the term "work function" can be most accurately described as which of the following?
The photoelectric effect is a phenomenon that has led to many important scientific discoveries. Light of a particular wavelength is shined onto a piece of metal, showering the metal with photons. Wavelength is inversely related to a photon's energy. That is, with a smaller wavelength, the photon has greater energy. The wavelength of the light is decreased until a detector next to the metal senses that electrons are being ejected from the metal. This sensor also tells us how many electrons are ejected per second, which we call electrical current. At this point, any additional decrease in wavelength does not affect the number of electrons ejected. This point is called the metal's work function. However, if we then begin to increase the intensity of the light being shone (meaning the amount of light as opposed to the light's wavelength), the number of electrons picked up by the sensor increases.
Based on the information in the passage, the term "work function" can be most accurately described as which of the following?
The correct answer is that it is the point at which the energy of the photons is barely enough to eject electrons. We know this because, as the passage says, decreasing the wavelength (increasing the energy) of the photons does not eject electrons until exactly this point. This implies that this gradual increase in photon energy passed the threshold we are calling the "work function" and led to electrons being ejected.
The correct answer is that it is the point at which the energy of the photons is barely enough to eject electrons. We know this because, as the passage says, decreasing the wavelength (increasing the energy) of the photons does not eject electrons until exactly this point. This implies that this gradual increase in photon energy passed the threshold we are calling the "work function" and led to electrons being ejected.
Compare your answer with the correct one above
The photoelectric effect is a phenomenon that has led to many important scientific discoveries. Light of a particular wavelength is shined onto a piece of metal, showering the metal with photons. Wavelength is inversely related to a photon's energy. That is, with a smaller wavelength, the photon has greater energy. The wavelength of the light is decreased until a detector next to the metal senses that electrons are being ejected from the metal. This sensor also tells us how many electrons are ejected per second, which we call electrical current. At this point, any additional decrease in wavelength does not affect the number of electrons ejected. This point is called the metal's work function. However, if we then begin to increase the intensity of the light being shone (meaning the amount of light as opposed to the light's wavelength), the number of electrons picked up by the sensor increases.
According to the information in the passage, what can we infer would happen if the intensity of the light were decreased immediately after reaching the work function?
The photoelectric effect is a phenomenon that has led to many important scientific discoveries. Light of a particular wavelength is shined onto a piece of metal, showering the metal with photons. Wavelength is inversely related to a photon's energy. That is, with a smaller wavelength, the photon has greater energy. The wavelength of the light is decreased until a detector next to the metal senses that electrons are being ejected from the metal. This sensor also tells us how many electrons are ejected per second, which we call electrical current. At this point, any additional decrease in wavelength does not affect the number of electrons ejected. This point is called the metal's work function. However, if we then begin to increase the intensity of the light being shone (meaning the amount of light as opposed to the light's wavelength), the number of electrons picked up by the sensor increases.
According to the information in the passage, what can we infer would happen if the intensity of the light were decreased immediately after reaching the work function?
The correct answer is that the current would remain, but it would decrease. At the end of the passage, we are told that intensity of the light affects the current in a direct relationship. That is, more intensity means greater current. Therefore, as we have seen that the presence of a current is related to the wavelength of the light used, we know that the current would remain. Furthermore, as we have decreased the intensity, we know that this current would simply decrease.
The correct answer is that the current would remain, but it would decrease. At the end of the passage, we are told that intensity of the light affects the current in a direct relationship. That is, more intensity means greater current. Therefore, as we have seen that the presence of a current is related to the wavelength of the light used, we know that the current would remain. Furthermore, as we have decreased the intensity, we know that this current would simply decrease.
Compare your answer with the correct one above
The photoelectric effect is a phenomenon that has led to many important scientific discoveries. Light of a particular wavelength is shined onto a piece of metal, showering the metal with photons. Wavelength is inversely related to a photon's energy. That is, with a smaller wavelength, the photon has greater energy. The wavelength of the light is decreased until a detector next to the metal senses that electrons are being ejected from the metal. This sensor also tells us how many electrons are ejected per second, which we call electrical current. At this point, any additional decrease in wavelength does not affect the number of electrons ejected. This point is called the metal's work function. However, if we then begin to increase the intensity of the light being shone (meaning the amount of light as opposed to the light's wavelength), the number of electrons picked up by the sensor increases.
Light intensity can best be described as which of the following?
The photoelectric effect is a phenomenon that has led to many important scientific discoveries. Light of a particular wavelength is shined onto a piece of metal, showering the metal with photons. Wavelength is inversely related to a photon's energy. That is, with a smaller wavelength, the photon has greater energy. The wavelength of the light is decreased until a detector next to the metal senses that electrons are being ejected from the metal. This sensor also tells us how many electrons are ejected per second, which we call electrical current. At this point, any additional decrease in wavelength does not affect the number of electrons ejected. This point is called the metal's work function. However, if we then begin to increase the intensity of the light being shone (meaning the amount of light as opposed to the light's wavelength), the number of electrons picked up by the sensor increases.
Light intensity can best be described as which of the following?
The correct answer is the number of photons. In the passage, we are told that the intensity of a light is related to the amount of light used. As light can be quantified in terms of photons, we know that this means that more intensity implies more photons. Any answer related to energy (including wavelength, force, and color) are incorrect because energy does not directly affect number of photons emitted and the speed of light is always the same.
The correct answer is the number of photons. In the passage, we are told that the intensity of a light is related to the amount of light used. As light can be quantified in terms of photons, we know that this means that more intensity implies more photons. Any answer related to energy (including wavelength, force, and color) are incorrect because energy does not directly affect number of photons emitted and the speed of light is always the same.
Compare your answer with the correct one above
A particle accelerator functions by exerting a magnetic field on charged particles which are shot into the accelerator. The magnetic field causes the charged particles to move around in a circle of radius 
that can be predicted by the following equation, where 
is the mass of the particle in kilograms, 
is the initial speed at which the particle was shot in meters per second, 
is the charge of the particle in Coulombs, and 
is the strength of the magnetic field in Tesla.
If a given magnetic field's strength 
and its radius 
, what would the radius 
be at 
?
A particle accelerator functions by exerting a magnetic field on charged particles which are shot into the accelerator. The magnetic field causes the charged particles to move around in a circle of radius
If a given magnetic field's strength
The correct answer is 
. We know by the equation that 
and 
are inversely related. As one increases, the other decreases, and vice versa. Therefore, if 
is tripled, 
must be divided by 
.
The correct answer is
Compare your answer with the correct one above
A particle accelerator functions by exerting a magnetic field on charged particles which are shot into the accelerator. The magnetic field causes the charged particles to move around in a circle of radius that can be predicted by the following equation, where is the mass of the particle in kilograms, is the initial speed at which the particle was shot in meters per second, is the charge of the particle in Coulombs, and is the strength of the magnetic field in Tesla.
A proton weighs approximately 
amu (atomic mass units) and has a charge of 
C. An electron has the same magnitude of charge, but it has about 
of the proton's mass. What would happen to radius 
if we were to suddenly switch the particle in the accelerator from a proton to an electron, keeping all of the other conditions the same?
A particle accelerator functions by exerting a magnetic field on charged particles which are shot into the accelerator. The magnetic field causes the charged particles to move around in a circle of radius
A proton weighs approximately
The correct answer is that radius 
would decrease 
-fold. With a smaller mass, we know by the given equation that the radius would change in proportion with the change in particle mass. Therefore, if the mass decreased 
-fold, so would radius 
.
The correct answer is that radius
Compare your answer with the correct one above
A particle separator functions by using a magnetic field and an electric field pointing perpendicularly. When a charged particle is launched into the particle separator, a constant electric force is exerted on the particle proportional to the particle's charge. Additionally, the magnetic field exerts a force on the particle that is in the opposite direction of the electric force and that is proportional to the particle's charge and velocity. A particle will make it through the particle separator only if the opposing magnetic forces and electric forces are equal in magnitude as they will not cause a net change in the particle's direction.
What can we infer would happen if a proton (a particle with a positive charge) were shot into the particle accelerator with an extremely low speed?
A particle separator functions by using a magnetic field and an electric field pointing perpendicularly. When a charged particle is launched into the particle separator, a constant electric force is exerted on the particle proportional to the particle's charge. Additionally, the magnetic field exerts a force on the particle that is in the opposite direction of the electric force and that is proportional to the particle's charge and velocity. A particle will make it through the particle separator only if the opposing magnetic forces and electric forces are equal in magnitude as they will not cause a net change in the particle's direction.
What can we infer would happen if a proton (a particle with a positive charge) were shot into the particle accelerator with an extremely low speed?
The correct answer is that the particle would move in the direction of the electric force. For this question, it is important to remember that we are inferring. This is a key skill in scientific research. Although we do not know the exact parameters, since we know that the magnetic force depends on bothvelocity and charge, we can make the inference that with a low velocity, the proton will not experience a strong magnetic force. Therefore, it is most probable that the particle will move in the same direction as the force produced by the electric field.
The correct answer is that the particle would move in the direction of the electric force. For this question, it is important to remember that we are inferring. This is a key skill in scientific research. Although we do not know the exact parameters, since we know that the magnetic force depends on bothvelocity and charge, we can make the inference that with a low velocity, the proton will not experience a strong magnetic force. Therefore, it is most probable that the particle will move in the same direction as the force produced by the electric field.
Compare your answer with the correct one above
Sound waves travel through a medium by mechanically disturbing the particles of that medium. As particles in the medium are displaced by the sound wave, they in turn act upon neighboring particles. In this fashion, the wave travels through the medium through a parallel series of disturbed particles. Like in other forms of motion, the rate at which the sound wave travels can be measured by dividing the distance over which the wave travels by the time required for it to do so.
Study 1
A group of students hypothesizes that the velocity of sound is dependent upon the density of the medium through which it passes. They propose that with more matter in a given space, each particle needs to travel a shorter distance to disturb the adjacent particles. Using two microphones and a high speed recording device, the students measured the delay from the first microphone to the second. They chose a variety of media, shown in Table 1, and measured the velocity of sound through each using their two-microphone setup. The results are found in Table 1.
Study 2
The students wanted to test their hypothesis by using the same medium at different densities. To do this, they heated pure water to various temperatures and repeated the procedure described in Study 1. Their results can be found in Table 2.
If the temperature of iron were raised slightly in Study 1, what would be the most likely result?
Sound waves travel through a medium by mechanically disturbing the particles of that medium. As particles in the medium are displaced by the sound wave, they in turn act upon neighboring particles. In this fashion, the wave travels through the medium through a parallel series of disturbed particles. Like in other forms of motion, the rate at which the sound wave travels can be measured by dividing the distance over which the wave travels by the time required for it to do so.
Study 1
A group of students hypothesizes that the velocity of sound is dependent upon the density of the medium through which it passes. They propose that with more matter in a given space, each particle needs to travel a shorter distance to disturb the adjacent particles. Using two microphones and a high speed recording device, the students measured the delay from the first microphone to the second. They chose a variety of media, shown in Table 1, and measured the velocity of sound through each using their two-microphone setup. The results are found in Table 1.
Study 2
The students wanted to test their hypothesis by using the same medium at different densities. To do this, they heated pure water to various temperatures and repeated the procedure described in Study 1. Their results can be found in Table 2.
If the temperature of iron were raised slightly in Study 1, what would be the most likely result?
Based on the results of Study 2, one can infer that increases in temperature tend to cause density to decrease and velocity to increase. Because this is the only temperature information in the passage, it is the best predictor of the effect of temperature change in iron.
Based on the results of Study 2, one can infer that increases in temperature tend to cause density to decrease and velocity to increase. Because this is the only temperature information in the passage, it is the best predictor of the effect of temperature change in iron.
Compare your answer with the correct one above
Sound waves travel through a medium by mechanically disturbing the particles of that medium. As particles in the medium are displaced by the sound wave, they in turn act upon neighboring particles. In this fashion, the wave travels through the medium through a parallel series of disturbed particles. Like in other forms of motion, the rate at which the sound wave travels can be measured by dividing the distance over which the wave travels by the time required for it to do so.
Study 1
A group of students hypothesizes that the velocity of sound is dependent upon the density of the medium through which it passes. They propose that with more matter in a given space, each particle needs to travel a shorter distance to disturb the adjacent particles. Using two microphones and a high speed recording device, the students measured the delay from the first microphone to the second. They chose a variety of media, shown in Table 1, and measured the velocity of sound through each using their two-microphone setup. The results are found in Table 1.
Study 2
The students wanted to test their hypothesis by using the same medium at different densities. To do this, they heated pure water to various temperatures and repeated the procedure described in Study 1. Their results can be found in Table 2.
Which study provides stronger evidence against the students' prediction and why?
Sound waves travel through a medium by mechanically disturbing the particles of that medium. As particles in the medium are displaced by the sound wave, they in turn act upon neighboring particles. In this fashion, the wave travels through the medium through a parallel series of disturbed particles. Like in other forms of motion, the rate at which the sound wave travels can be measured by dividing the distance over which the wave travels by the time required for it to do so.
Study 1
A group of students hypothesizes that the velocity of sound is dependent upon the density of the medium through which it passes. They propose that with more matter in a given space, each particle needs to travel a shorter distance to disturb the adjacent particles. Using two microphones and a high speed recording device, the students measured the delay from the first microphone to the second. They chose a variety of media, shown in Table 1, and measured the velocity of sound through each using their two-microphone setup. The results are found in Table 1.
Study 2
The students wanted to test their hypothesis by using the same medium at different densities. To do this, they heated pure water to various temperatures and repeated the procedure described in Study 1. Their results can be found in Table 2.
Which study provides stronger evidence against the students' prediction and why?
The students in the passage hypothesized that increased density would result in increased velocity of sound through that medium. Study 2 provides the most evidence to the contrary by showing decreasing densities linked to increasing velocities.
The students in the passage hypothesized that increased density would result in increased velocity of sound through that medium. Study 2 provides the most evidence to the contrary by showing decreasing densities linked to increasing velocities.
Compare your answer with the correct one above
Sound waves travel through a medium by mechanically disturbing the particles of that medium. As particles in the medium are displaced by the sound wave, they in turn act upon neighboring particles. In this fashion, the wave travels through the medium through a parallel series of disturbed particles. Like in other forms of motion, the rate at which the sound wave travels can be measured by dividing the distance over which the wave travels by the time required for it to do so.
Study 1
A group of students hypothesizes that the velocity of sound is dependent upon the density of the medium through which it passes. They propose that with more matter in a given space, each particle needs to travel a shorter distance to disturb the adjacent particles. Using two microphones and a high speed recording device, the students measured the delay from the first microphone to the second. They chose a variety of media, shown in Table 1, and measured the velocity of sound through each using their two-microphone setup. The results are found in Table 1.
Study 2
The students wanted to test their hypothesis by using the same medium at different densities. To do this, they heated pure water to various temperatures and repeated the procedure described in Study 1. Their results can be found in Table 2.
According to the information in the passage, what is necessary for sound to travel through a medium?
Sound waves travel through a medium by mechanically disturbing the particles of that medium. As particles in the medium are displaced by the sound wave, they in turn act upon neighboring particles. In this fashion, the wave travels through the medium through a parallel series of disturbed particles. Like in other forms of motion, the rate at which the sound wave travels can be measured by dividing the distance over which the wave travels by the time required for it to do so.
Study 1
A group of students hypothesizes that the velocity of sound is dependent upon the density of the medium through which it passes. They propose that with more matter in a given space, each particle needs to travel a shorter distance to disturb the adjacent particles. Using two microphones and a high speed recording device, the students measured the delay from the first microphone to the second. They chose a variety of media, shown in Table 1, and measured the velocity of sound through each using their two-microphone setup. The results are found in Table 1.
Study 2
The students wanted to test their hypothesis by using the same medium at different densities. To do this, they heated pure water to various temperatures and repeated the procedure described in Study 1. Their results can be found in Table 2.
According to the information in the passage, what is necessary for sound to travel through a medium?
The passage states that sound waves travel by mechanically disturbing particles. Without a medium with particles close enough to interact physically, there would be no transfer of mechanical energy through the medium.
The remaining answers list conditions of the studies used to test the students' hypothesis about density and sound velocity. These are not essential for sound to travel through a medium.
The passage states that sound waves travel by mechanically disturbing particles. Without a medium with particles close enough to interact physically, there would be no transfer of mechanical energy through the medium.
The remaining answers list conditions of the studies used to test the students' hypothesis about density and sound velocity. These are not essential for sound to travel through a medium.
Compare your answer with the correct one above
Sound waves travel through a medium by mechanically disturbing the particles of that medium. As particles in the medium are displaced by the sound wave, they in turn act upon neighboring particles. In this fashion, the wave travels through the medium through a parallel series of disturbed particles. Like in other forms of motion, the rate at which the sound wave travels can be measured by dividing the distance over which the wave travels by the time required for it to do so.
Study 1
A group of students hypothesizes that the velocity of sound is dependent upon the density of the medium through which it passes. They propose that with more matter in a given space, each particle needs to travel a shorter distance to disturb the adjacent particles. Using two microphones and a high speed recording device, the students measured the delay from the first microphone to the second. They chose a variety of media, shown in Table 1, and measured the velocity of sound through each using their two-microphone setup. The results are found in Table 1.
Study 2
The students wanted to test their hypothesis by using the same medium at different densities. To do this, they heated pure water to various temperatures and repeated the procedure described in Study 1. Their results can be found in Table 2.
In Study 1, if the students were to double the length of the samples of media, what would happen to the velocity of sound through those media?
Sound waves travel through a medium by mechanically disturbing the particles of that medium. As particles in the medium are displaced by the sound wave, they in turn act upon neighboring particles. In this fashion, the wave travels through the medium through a parallel series of disturbed particles. Like in other forms of motion, the rate at which the sound wave travels can be measured by dividing the distance over which the wave travels by the time required for it to do so.
Study 1
A group of students hypothesizes that the velocity of sound is dependent upon the density of the medium through which it passes. They propose that with more matter in a given space, each particle needs to travel a shorter distance to disturb the adjacent particles. Using two microphones and a high speed recording device, the students measured the delay from the first microphone to the second. They chose a variety of media, shown in Table 1, and measured the velocity of sound through each using their two-microphone setup. The results are found in Table 1.
Study 2
The students wanted to test their hypothesis by using the same medium at different densities. To do this, they heated pure water to various temperatures and repeated the procedure described in Study 1. Their results can be found in Table 2.
In Study 1, if the students were to double the length of the samples of media, what would happen to the velocity of sound through those media?
According to the passage, velocity of sound is found by dividing distance by time. Any increase in distance traveled would cause the time required for travel to increase proportionally. In this manner, velocity would remain constant if the students were to double the length of media samples in Study 1.
According to the passage, velocity of sound is found by dividing distance by time. Any increase in distance traveled would cause the time required for travel to increase proportionally. In this manner, velocity would remain constant if the students were to double the length of media samples in Study 1.
Compare your answer with the correct one above
A physicist wishes to study the trajectory of a ball launched horizontally. She varies parameters such as the launching velocity, starting height, and mass of the ball. For each trajectory, she records the time of flight (in seconds) and horizontal displacement (in meters). She assumes air resistance is negligible.
Figure 1
Using all of the data she collects, she constructs the following table:
Table 1
Based on the data presented in the table, what appears to be the relationship between the mass of the ball and the time of flight?
A physicist wishes to study the trajectory of a ball launched horizontally. She varies parameters such as the launching velocity, starting height, and mass of the ball. For each trajectory, she records the time of flight (in seconds) and horizontal displacement (in meters). She assumes air resistance is negligible.
Figure 1
Using all of the data she collects, she constructs the following table:
Table 1
Based on the data presented in the table, what appears to be the relationship between the mass of the ball and the time of flight?
In trial 3, the time of flight remains the same as the mass of the ball is varied.
In trial 3, the time of flight remains the same as the mass of the ball is varied.
Compare your answer with the correct one above
A physicist wishes to study the trajectory of a ball launched horizontally. She varies parameters such as the launching velocity, starting height, and mass of the ball. For each trajectory, she records the time of flight (in seconds) and horizontal displacement (in meters). She assumes air resistance is negligible.
Figure 1
Using all of the data she collects, she constructs the following table:
Table 1
In which trial(s) did the time of flight change between data points?
A physicist wishes to study the trajectory of a ball launched horizontally. She varies parameters such as the launching velocity, starting height, and mass of the ball. For each trajectory, she records the time of flight (in seconds) and horizontal displacement (in meters). She assumes air resistance is negligible.
Figure 1
Using all of the data she collects, she constructs the following table:
Table 1
In which trial(s) did the time of flight change between data points?
By inspecting the table, we see that the time of flight changed between data points for Trial 2 only.
By inspecting the table, we see that the time of flight changed between data points for Trial 2 only.
Compare your answer with the correct one above
Sometimes scientists need to scale down experiments because collecting full-scale data may not be practical or possible. Most of the time, the data collected during a small scale-experiment is an accurate indicator of full-scale results. For example, research of craters on the Earth’s surface has indicated that the Earth has experienced a history of massive meteor collisions. It has been hypothesized that, amongst other things, these impacting meteorites caused the Earth’s oceans to vaporize. The detrimental effects associated with meteor collisions would have made the planet to be uninhabitable to humans. Due to these adverse effects, an experiment that could produce meteor-sized craters would not be possible in a full-scale setting.
Researchers have developed small-scale experiments that are exemplary of Newton’s three laws of motion. Newton’s first law states that an object in motion will stay in motion unless it is acted on by another force. This phenomenon is known as inertia. The second law comes in the form of an equation that calculates how much force is exerted on two colliding objects with respect to mass and acceleration. In other words force is equal to the mass of an object multiplied by its acceleration. The third law states that for every action there is an equal and opposite reaction. In other words, forces always occur in pairs. A counter force that is equal in magnitude and opposite in direction compliments each force in a particular direction. For example, if you push downwards on a table then the table, in theory, pushes upwards with the same force.
In a particular small-scale exercise, students were asked to design an experiment in which two “meteorites” would be dropped into a medium of sand and the subsequent crater diameters would be measured. Afterwards, the sand would be leveled and the experiment would be repeated. The students were asked to identify all of the factors that could affect the formation of the craters. This was done in order to ensure that each experiment was testing one independent and one dependent variable at a time. Otherwise, it would be unclear which variable is causing the observed effect. Possible variables that could alter the outcome of the experiment included but were not limited to the following: height of the fall, speed of the “meteorite,” angle of impact, and the mass of meteorite.
Consider an experiment that seeks to identify the mass of the meteorite analog. All other variables would have to remain constant in order to ensure accurate results. In order to do this, the height of the fall was set to one meter. The object was placed on top of a vertical meter stick. In order to keep the acceleration and height of the drop constant, it was rolled off of the stick instead of being pushed or simply dropped. Last, a protractor was used to keep the meter stick at a ninety-degree angle. In the procedure, a marble and a golf ball were used as “meteorites” of different masses.
The results of the experiment were recorded in the table and figure provided.
| | Crater Diameter (cm) | | |
| --------------------------- | -------------------------- | ---- |
| Trial Number | | |
| | Marble (mass = 4g) | Golf ball (mass = 46g) | |
| 1 | 4.5 | 7.75 |
| 2 | 4.5 | 6 |
| 3 | 4 | 5.5 |
| 4 | 3 | 6 |
| 5 | 3 | 6.5 |
| 6 | 3.5 | 7 |
| 7 | 3 | 5 |
| 8 | 3 | 5 |
| 9 | 3 | 7 |
| 10 | 3.5 | 6 |
| | Average | Average | |
| | 3.5 cm | 6.175 cm | |
Predict what would happen to the crater size if the experiment changed the velocity instead of the mass of the objects.
Sometimes scientists need to scale down experiments because collecting full-scale data may not be practical or possible. Most of the time, the data collected during a small scale-experiment is an accurate indicator of full-scale results. For example, research of craters on the Earth’s surface has indicated that the Earth has experienced a history of massive meteor collisions. It has been hypothesized that, amongst other things, these impacting meteorites caused the Earth’s oceans to vaporize. The detrimental effects associated with meteor collisions would have made the planet to be uninhabitable to humans. Due to these adverse effects, an experiment that could produce meteor-sized craters would not be possible in a full-scale setting.
Researchers have developed small-scale experiments that are exemplary of Newton’s three laws of motion. Newton’s first law states that an object in motion will stay in motion unless it is acted on by another force. This phenomenon is known as inertia. The second law comes in the form of an equation that calculates how much force is exerted on two colliding objects with respect to mass and acceleration. In other words force is equal to the mass of an object multiplied by its acceleration. The third law states that for every action there is an equal and opposite reaction. In other words, forces always occur in pairs. A counter force that is equal in magnitude and opposite in direction compliments each force in a particular direction. For example, if you push downwards on a table then the table, in theory, pushes upwards with the same force.
In a particular small-scale exercise, students were asked to design an experiment in which two “meteorites” would be dropped into a medium of sand and the subsequent crater diameters would be measured. Afterwards, the sand would be leveled and the experiment would be repeated. The students were asked to identify all of the factors that could affect the formation of the craters. This was done in order to ensure that each experiment was testing one independent and one dependent variable at a time. Otherwise, it would be unclear which variable is causing the observed effect. Possible variables that could alter the outcome of the experiment included but were not limited to the following: height of the fall, speed of the “meteorite,” angle of impact, and the mass of meteorite.
Consider an experiment that seeks to identify the mass of the meteorite analog. All other variables would have to remain constant in order to ensure accurate results. In order to do this, the height of the fall was set to one meter. The object was placed on top of a vertical meter stick. In order to keep the acceleration and height of the drop constant, it was rolled off of the stick instead of being pushed or simply dropped. Last, a protractor was used to keep the meter stick at a ninety-degree angle. In the procedure, a marble and a golf ball were used as “meteorites” of different masses.
The results of the experiment were recorded in the table and figure provided.
| | Crater Diameter (cm) | | | | --------------------------- | -------------------------- | ---- | | Trial Number | | | | | Marble (mass = 4g) | Golf ball (mass = 46g) | | | 1 | 4.5 | 7.75 | | 2 | 4.5 | 6 | | 3 | 4 | 5.5 | | 4 | 3 | 6 | | 5 | 3 | 6.5 | | 6 | 3.5 | 7 | | 7 | 3 | 5 | | 8 | 3 | 5 | | 9 | 3 | 7 | | 10 | 3.5 | 6 | | | Average | Average | | | | 3.5 cm | 6.175 cm | |
Predict what would happen to the crater size if the experiment changed the velocity instead of the mass of the objects.
Since kinetic energy has an exponential relationship with velocity, the craters would grow exponentially in size as the velocity increases. This is because the amount of force increases in the same fashion; therefore, we know that an impact zone is affected more by an object’s velocity than its mass.
Since kinetic energy has an exponential relationship with velocity, the craters would grow exponentially in size as the velocity increases. This is because the amount of force increases in the same fashion; therefore, we know that an impact zone is affected more by an object’s velocity than its mass.
Compare your answer with the correct one above