ACT Science : Physics
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Example Questions
Example Question #1281 : Act Science
The period of a simple pendulum 
Student 1: The period of a pendulum depends on two factors: the mass of the pendulum's bob (the object swinging at the end of the pendulum) and the length of the pendulum. The height at which the pendulum is originally dropped does not affect the period 
Student 2: The period of a pendulum 
The two students ran a series of trials to measure the period of a simple pendulum using varying weights and lengths. The students did not measure height as a factor. The results of the trials can be seen in the table below:
On which of the following points would the scientists most likely disagree?
Two children of identical masses swinging on swings of different length would show different swinging periods.
Length of a pendulum is not important to consider when measuring period 
Increasing the gravitational force on a pendulum will affect its period.
Two children of different masses swinging on identical swings would show the exact same swinging period.
A child swinging at a height of one meter would show the same period of swinging as a child swinging at a height of two meters.
Two children of different masses swinging on identical swings would show the exact same swinging period.
The correct answer is "Two children of different masses swinging on identical swings would show the exact same swinging period." According to the passage, only Student 2 would agree that the children would show the same period of swinging, while Student 1 would argue that they would differ. Gravitational force was not mentioned in the passage (although it is a true statement) and both students agree that the length is important to consider.
Example Question #32 : How To Find Conflicting Viewpoints In Physics
The period of a simple pendulum
Student 1: The period of a pendulum depends on two factors: the mass of the pendulum's bob (the object swinging at the end of the pendulum) and the length of the pendulum. The height at which the pendulum is originally dropped does not affect the period
Student 2: The period of a pendulum
The two students ran a series of trials to measure the period of a simple pendulum using varying weights and lengths. The students did not measure height as a factor. The results of the trials can be seen in the table below:
Before analyzing the data collected, the two students go out into a local playground and use the swing set to test their hypotheses in an approximate manner. Student 1 and Student 2 are almost exactly the same mass, so Student 2 swings wearing his backpack full of books. Both students begin swinging from the same height and swing exactly three times each in exactly twelve seconds. Whose hypothesis has been supported in this brief trial?
More information is needed.
Student 1's
Neither student's
Student 2's
Both Student 1's and Student 2's
Student 2's
The answer is Student 2's hypothesis. Since the students swung the same amount of times over the same period of time, we can extrapolate that the "period" involved in this pendulum was the same. To derive this, we need an understanding of the definition of a pendulum's period as defined by the passage. Since the students varied in mass because of Student 2's backpack, we can see that this supports the hypothesis that mass does not affect a pendulum's period.
Example Question #33 : How To Find Conflicting Viewpoints In Physics
As part of an engineering competition, a group of students are asked to design a flying robot that simulates the way real birds fly. Below, three of the students give their explanations for how bird flight occurs.
Student 1:
Birds are able to fly due to the shape of their wings. Bird wings are convex on their upper sides, while their lower sides are usually concave. This type of shape is called an airfoil. When a wing travels through the air, air passing over the top of the wing must travel a greater distance than air passing under the wing. The stream of air passing over the wing and the stream of air passing under the wing meet together at the tail end of the wing. In order for both streams of air to meet at the same point behind the wing, the air above the wing, which travels a greater distance, must travel faster than the air below the wing.
When a volume of air travels more quickly over a distance, its molecules are spread out over a greater distance. As a result, the air traveling over the top of a wing has a lower pressure than the air traveling under the wing. Because the wing has a region of low pressure above it and a region of relative high pressure below it, it experiences a net upward force. When this upward force is greater than or equal to the bird's weight, or the force exerted on a bird by gravity, the bird is able to fly.
The magnitude of the upward force depends on the speed at which air flows across the wing and on the corresponding difference in pressure over and under the wing. When birds flap their wings, they increase the speed of air flowing across their wings, thus producing a greater upward force.
Student 2:
There are two components to bird flight: lift and thrust. "Lift" refers to the upward force that allows a bird to stay aloft in the air despite its weight, while "thrust" refers to the horizontal force that allows a bird to move forward through the air. Birds are able to fly because they do not hold their wings perfectly horizontally. Instead, their wings are angled slightly upward. The angle at which a wing is inclined upward, with respect to the horizontal, is called its "angle of attack."
Air is not an ideal gas; instead, it has viscosity. This means that the air flowing close to a solid object tends to follow the curves of that object. When air encounters a bird's wing, it follows the incline of the wing. Because of the wing's angle of attack, the air is directed downward and back. The air continues to move downward, even after it has left the wing. This movement of the air creates an opposing force that pushes the bird upward and forward.
Thus, the angle of attack of a bird's wings accounts for both the lift and thrust components of a bird's flight.
Student 3:
Birds are able to fly because the way in which they move their wings allows them to create a net movement of air downward and backward. The flapping of a bird's wings can be understood as being composed of two parts: a downstroke, during which the bird moves its wings down, and an upstroke, during which the bird moves its wings up. During a downstroke, a bird displaces a quantity of air downward and behind it. During an upstroke, however, the bird's wings are angled upward in a way that displaces less air, and its wing feathers rotate to allow air to pass through them. Thus, on the upstroke, the bird much exerts less force on the air than it does on the downstroke.
Suppose that, in designing a hovercraft, engineers position a fan so that it blows out air straight down from the bottom of the hovercraft. Given that Student 2's explanation is correct, this would generate which of the following?
Thrust
Neither lift nor thrust
Lift
Both lift and thrust
Lift
Student 2 states that the movement of air creates and equal and opposing force which pushes a bird (or any other flying object) in the opposite direction. So, if the fan on the hovercraft blows air downward, this would generate an upward force which acts on the hovercraft. Student 2 states that the upward force experienced by a flying object is called lift.
Example Question #34 : How To Find Conflicting Viewpoints In Physics
As part of an engineering competition, a group of students are asked to design a flying robot that simulates the way real birds fly. Below, three of the students give their explanations for how bird flight occurs.
Student 1:
Birds are able to fly due to the shape of their wings. Bird wings are convex on their upper sides, while their lower sides are usually concave. This type of shape is called an airfoil. When a wing travels through the air, air passing over the top of the wing must travel a greater distance than air passing under the wing. The stream of air passing over the wing and the stream of air passing under the wing meet together at the tail end of the wing. In order for both streams of air to meet at the same point behind the wing, the air above the wing, which travels a greater distance, must travel faster than the air below the wing.
When a volume of air travels more quickly over a distance, its molecules are spread out over a greater distance. As a result, the air traveling over the top of a wing has a lower pressure than the air traveling under the wing. Because the wing has a region of low pressure above it and a region of relative high pressure below it, it experiences a net upward force. When this upward force is greater than or equal to the bird's weight, or the force exerted on a bird by gravity, the bird is able to fly.
The magnitude of the upward force depends on the speed at which air flows across the wing and on the corresponding difference in pressure over and under the wing. When birds flap their wings, they increase the speed of air flowing across their wings, thus producing a greater upward force.
Student 2:
There are two components to bird flight: lift and thrust. "Lift" refers to the upward force that allows a bird to stay aloft in the air despite its weight, while "thrust" refers to the horizontal force that allows a bird to move forward through the air. Birds are able to fly because they do not hold their wings perfectly horizontally. Instead, their wings are angled slightly upward. The angle at which a wing is inclined upward, with respect to the horizontal, is called its "angle of attack."
Air is not an ideal gas; instead, it has viscosity. This means that the air flowing close to a solid object tends to follow the curves of that object. When air encounters a bird's wing, it follows the incline of the wing. Because of the wing's angle of attack, the air is directed downward and back. The air continues to move downward, even after it has left the wing. This movement of the air creates an opposing force that pushes the bird upward and forward.
Thus, the angle of attack of a bird's wings accounts for both the lift and thrust components of a bird's flight.
Student 3:
Birds are able to fly because the way in which they move their wings allows them to create a net movement of air downward and backward. The flapping of a bird's wings can be understood as being composed of two parts: a downstroke, during which the bird moves its wings down, and an upstroke, during which the bird moves its wings up. During a downstroke, a bird displaces a quantity of air downward and behind it. During an upstroke, however, the bird's wings are angled upward in a way that displaces less air, and its wing feathers rotate to allow air to pass through them. Thus, on the upstroke, the bird much exerts less force on the air than it does on the downstroke.
Suppose that Student 1 argues that his explanation of bird flight also applies to flight in general. Which of the following, if found, provides the strongest evidence against the explanation given by Student 1?
Many birds are not able to stay aloft in the air without flapping their wings
Some airfoils have upper and lower sides that are both convex
Certain airplanes do not have wings with airfoil shapes, but are able to fly
The pressure of air depends not only on the speed at which air is moving, but also on the air's temperature
Certain birds are not able to fly, though they have wings that have the shape of airfoils
Certain airplanes do not have wings with airfoil shapes, but are able to fly
Student 1 gives an explanation of flight in terms of the airfoil shapes of wings, which, he says, generate the upward force that allows a bird to stay aloft. If his explanation applies to flight in general, we can expect all objects that fly to have wings with airfoil shapes; however, if some airplanes do not have wings with airfoil shapes but are still able to fly, this would directly contradict Student 1's idea.
The fact that some airfoils have upper and lower sides that are both convex is not the best answer, because Student 1's explanation would still work if these kinds of airfoils create a difference in the air pressure above and below them.
Example Question #35 : How To Find Conflicting Viewpoints In Physics
As part of an engineering competition, a group of students are asked to design a flying robot that simulates the way real birds fly. Below, three of the students give their explanations for how bird flight occurs.
Student 1:
Birds are able to fly due to the shape of their wings. Bird wings are convex on their upper sides, while their lower sides are usually concave. This type of shape is called an airfoil. When a wing travels through the air, air passing over the top of the wing must travel a greater distance than air passing under the wing. The stream of air passing over the wing and the stream of air passing under the wing meet together at the tail end of the wing. In order for both streams of air to meet at the same point behind the wing, the air above the wing, which travels a greater distance, must travel faster than the air below the wing.
When a volume of air travels more quickly over a distance, its molecules are spread out over a greater distance. As a result, the air traveling over the top of a wing has a lower pressure than the air traveling under the wing. Because the wing has a region of low pressure above it and a region of relative high pressure below it, it experiences a net upward force. When this upward force is greater than or equal to the bird's weight, or the force exerted on a bird by gravity, the bird is able to fly.
The magnitude of the upward force depends on the speed at which air flows across the wing and on the corresponding difference in pressure over and under the wing. When birds flap their wings, they increase the speed of air flowing across their wings, thus producing a greater upward force.
Student 2:
There are two components to bird flight: lift and thrust. "Lift" refers to the upward force that allows a bird to stay aloft in the air despite its weight, while "thrust" refers to the horizontal force that allows a bird to move forward through the air. Birds are able to fly because they do not hold their wings perfectly horizontally. Instead, their wings are angled slightly upward. The angle at which a wing is inclined upward, with respect to the horizontal, is called its "angle of attack."
Air is not an ideal gas; instead, it has viscosity. This means that the air flowing close to a solid object tends to follow the curves of that object. When air encounters a bird's wing, it follows the incline of the wing. Because of the wing's angle of attack, the air is directed downward and back. The air continues to move downward, even after it has left the wing. This movement of the air creates an opposing force that pushes the bird upward and forward.
Thus, the angle of attack of a bird's wings accounts for both the lift and thrust components of a bird's flight.
Student 3:
Birds are able to fly because the way in which they move their wings allows them to create a net movement of air downward and backward. The flapping of a bird's wings can be understood as being composed of two parts: a downstroke, during which the bird moves its wings down, and an upstroke, during which the bird moves its wings up. During a downstroke, a bird displaces a quantity of air downward and behind it. During an upstroke, however, the bird's wings are angled upward in a way that displaces less air, and its wing feathers rotate to allow air to pass through them. Thus, on the upstroke, the bird much exerts less force on the air than it does on the downstroke.
Which of the following, if found, provides the strongest evidence against the explanation of flight given by Student 3?
The way in which a bird flaps its wings changes as the bird takes off, flies, and descends to land
Some birds are able to hover, staying in the same position in the air as they flap their wings
Some birds cannot continue to fly without flapping their wings
Some birds can fly for extended periods of time without moving their wings
Birds move their wings in an elliptical way as they flap, tilting their wings down and then rotating them up
Some birds can fly for extended periods of time without moving their wings
Student 3's explanation of flight focuses on relative amounts of force that a bird exerts on the air during the downstroke and upstroke of its wings. His explanation requires that a bird move its wings; however, if some birds are able to fly without moving their wings, this would suggest that bird flight cannot be explained wholly by the relative amounts of force that wings exert on air when they move up and down.
Example Question #35 : How To Find Conflicting Viewpoints In Physics
As part of an engineering competition, a group of students are asked to design a flying robot that simulates the way real birds fly. Below, three of the students give their explanations for how bird flight occurs.
Student 1:
Birds are able to fly due to the shape of their wings. Bird wings are convex on their upper sides, while their lower sides are usually concave. This type of shape is called an airfoil. When a wing travels through the air, air passing over the top of the wing must travel a greater distance than air passing under the wing. The stream of air passing over the wing and the stream of air passing under the wing meet together at the tail end of the wing. In order for both streams of air to meet at the same point behind the wing, the air above the wing, which travels a greater distance, must travel faster than the air below the wing.
When a volume of air travels more quickly over a distance, its molecules are spread out over a greater distance. As a result, the air traveling over the top of a wing has a lower pressure than the air traveling under the wing. Because the wing has a region of low pressure above it and a region of relative high pressure below it, it experiences a net upward force. When this upward force is greater than or equal to the bird's weight, or the force exerted on a bird by gravity, the bird is able to fly.
The magnitude of the upward force depends on the speed at which air flows across the wing and on the corresponding difference in pressure over and under the wing. When birds flap their wings, they increase the speed of air flowing across their wings, thus producing a greater upward force.
Student 2:
There are two components to bird flight: lift and thrust. "Lift" refers to the upward force that allows a bird to stay aloft in the air despite its weight, while "thrust" refers to the horizontal force that allows a bird to move forward through the air. Birds are able to fly because they do not hold their wings perfectly horizontally. Instead, their wings are angled slightly upward. The angle at which a wing is inclined upward, with respect to the horizontal, is called its "angle of attack."
Air is not an ideal gas; instead, it has viscosity. This means that the air flowing close to a solid object tends to follow the curves of that object. When air encounters a bird's wing, it follows the incline of the wing. Because of the wing's angle of attack, the air is directed downward and back. The air continues to move downward, even after it has left the wing. This movement of the air creates an opposing force that pushes the bird upward and forward.
Thus, the angle of attack of a bird's wings accounts for both the lift and thrust components of a bird's flight.
Student 3:
Birds are able to fly because the way in which they move their wings allows them to create a net movement of air downward and backward. The flapping of a bird's wings can be understood as being composed of two parts: a downstroke, during which the bird moves its wings down, and an upstroke, during which the bird moves its wings up. During a downstroke, a bird displaces a quantity of air downward and behind it. During an upstroke, however, the bird's wings are angled upward in a way that displaces less air, and its wing feathers rotate to allow air to pass through them. Thus, on the upstroke, the bird much exerts less force on the air than it does on the downstroke.
Dragonflies have four membranous, flat, independently-moving wings. Which of the three students' explanations of bird flight cannot be used to explain how dragonflies fly?
Student 2
All three students' explanations can be used to explain how dragonflies fly
It is not possible to use any of the students' explanations to explain how dragonflies fly
Student 1
Student 3
Student 1
Student 1's explanation focuses on the difference in air pressure that is generated when air flows over and under a wing with the shape of an airfoil; however, since dragonflies have flat wings, Student 1's explanation would not explain how dragonfly wings allow dragonflies to fly.
Student 2 and Student 3's explanations, however, do not rely on a wing having a particular shape. Instead, Student 2 and Student 3 focus on the way that the angle of a wing directs air, or on the force exerted on air when wings flap. So, it is possible to use Student 2 and Student 3's explanations to explain dragonfly flight.
Example Question #36 : How To Find Conflicting Viewpoints In Physics
Scientist 1: This scientist claims that the current in a circuit flows from the positive side of a battery to the negative side of the battery. In other words, the protons in the circuit are responsible for the flow of electricity.
Scientist 2: This scientist asserts that the current in a circuit flows from the negative side of a battery to the positive side of the battery. In other words, the electrons in the circuit are responsible for the flow of electricity.
Experiment A: The scientists construct a circuit that contains just a battery, a switch and light bulb. The wiring is made of copper. The scientists turn the switch from off to on. It is noticed that the light bulb turns on.
Experiment B: The scientists have developed a novel metal that allows for only electrons to travel through the metal, but does not allow protons to travel through the metal. The scientists construct the same circuit as in Experiment A, using this material as the wiring. When the switch is turned on, the light bulb turns on.
Experiment C: The scientists have also constructed a metal that allows for only protons to travel through the metal, but does not allow for electrons to travel through the metal. The same circuit as in Experiment A is constructed, but with the wiring being made by this innovative metal. When the switch is turned on, the light bulb does not turn on.
What is the function of Experiment A?
This experiment proves Scientist 1's viewpoint
This experiment proves Scientist 2's viewpoint
It acts as a control experiment
There is no point to this experiment; no information is gained
It acts as a control experiment
Experiment A uses non-innovative components. This experiment uses a light bulb, copper wiring and a switch. These are all normal parts of a circuit. This experiment shows that the circuit setup works in terms of lighting the light bulb. This experiment was a control experiment to show the setup works.
Example Question #37 : How To Find Conflicting Viewpoints In Physics
Scientist 1: This scientist claims that the current in a circuit flows from the positive side of a battery to the negative side of the battery. In other words, the protons in the circuit are responsible for the flow of electricity.
Scientist 2: This scientist asserts that the current in a circuit flows from the negative side of a battery to the positive side of the battery. In other words, the electrons in the circuit are responsible for the flow of electricity.
Experiment A: The scientists construct a circuit that contains just a battery, a switch and light bulb. The wiring is made of copper. The scientists turn the switch from off to on. It is noticed that the light bulb turns on.
Experiment B: The scientists have developed a novel metal that allows for only electrons to travel through the metal, but does not allow protons to travel through the metal. The scientists construct the same circuit as in Experiment A, using this material as the wiring. When the switch is turned on, the light bulb turns on.
Experiment C: The scientists have also constructed a metal that allows for only protons to travel through the metal, but does not allow for electrons to travel through the metal. The same circuit as in Experiment A is constructed, but with the wiring being made by this innovative metal. When the switch is turned on, the light bulb does not turn on.
Whose viewpoints are supported or disproved by Experiment C?
Scientist 1's viewpoint is neither proved or disproved; Scientist 2's viewpoint is disproved
Scientist 1's viewpoint is disproved; Scientist 2's viewpoint is disproved
Scientist 1's viewpoint is disproved; Scientist 2's viewpoint is neither supported nor disproved
Scientist 1's viewpoint is supported; Scientist 2's viewpoint is supported
Scientist 1's viewpoint is disproved; Scientist 2's viewpoint is neither supported nor disproved
The circuit allows for the flow of protons and it is noticed that the light bulb does not turn on. Therefore the protons in the circuit are not responsible for the flow of electricity as the light bulb would turn on if there was a flow of electricity. Scientist 1's viewpoint is disproven. There is nothing said about the flow of electrons in this experiment and therefore Scientist 2's viewpoint is neither proven nor disproven.
Example Question #1291 : Act Science
Scientist 1: This scientist claims that the current in a circuit flows from the positive side of a battery to the negative side of the battery. In other words, the protons in the circuit are responsible for the flow of electricity.
Scientist 2: This scientist asserts that the current in a circuit flows from the negative side of a battery to the positive side of the battery. In other words, the electrons in the circuit are responsible for the flow of electricity.
Experiment A: The scientists construct a circuit that contains just a battery, a switch and light bulb. The wiring is made of copper. The scientists turn the switch from off to on. It is noticed that the light bulb turns on.
Experiment B: The scientists have developed a novel metal that allows for only electrons to travel through the metal, but does not allow protons to travel through the metal. The scientists construct the same circuit as in Experiment A, using this material as the wiring. When the switch is turned on, the light bulb turns on.
Experiment C: The scientists have also constructed a metal that allows for only protons to travel through the metal, but does not allow for electrons to travel through the metal. The same circuit as in Experiment A is constructed, but with the wiring being made by this innovative metal. When the switch is turned on, the light bulb does not turn on.
Whose viewpoint(s) does Experiment B support or disprove?
Supports Scientist 1's viewpoint; supports Scientist 2's viewpoint
Disproves both scientists' viewpoints
Does not prove or disprove Scientist 1's viewpoint; supports Scientist 2's viewpoint
Supports Scientist 1's viewpoint; Does not support or disprove Scientist 2's viewpoint
Does not prove or disprove Scientist 1's viewpoint; supports Scientist 2's viewpoint
The metal that the scientist have used for the wiring allows for the flow of electrons. It is noticed that in this experiment the light bulb does in fact turn on, meaning that there is a flow of electricity. Since only electrons are allowed to flow in the metal the electrons are responsible for the flow of electricity proving Scientist 2's point. This experiment does not show any about the protons; as the protons may also be responsible for the flow of electricity or they may not be. The experiment does not prove or disprove Scientist 1's viewpoint.
Example Question #1292 : Act Science
Scientist 1: This scientist claims that the current in a circuit flows from the positive side of a battery to the negative side of the battery. In other words, the protons in the circuit are responsible for the flow of electricity.
Scientist 2: This scientist asserts that the current in a circuit flows from the negative side of a battery to the positive side of the battery. In other words, the electrons in the circuit are responsible for the flow of electricity.
Experiment A: The scientists construct a circuit that contains just a battery, a switch and light bulb. The wiring is made of copper. The scientists turn the switch from off to on. It is noticed that the light bulb turns on.
Experiment B: The scientists have developed a novel metal that allows for only electrons to travel through the metal, but does not allow protons to travel through the metal. The scientists construct the same circuit as in Experiment A, using this material as the wiring. When the switch is turned on, the light bulb turns on.
Experiment C: The scientists have also constructed a metal that allows for only protons to travel through the metal, but does not allow for electrons to travel through the metal. The same circuit as in Experiment A is constructed, but with the wiring being made by this innovative metal. When the switch is turned on, the light bulb does not turn on.
Whose viewpoints are support or disproved by all of these experiments?
Scientist 1's viewpoint is supported; Scientist 2's viewpoint is disproven
Scientist 1's viewpoint is supported; Scientist 2's viewpoint is supported
Scientist 1's viewpoint is disproven; Scientist 2's viewpoint is supported
Scientist 1's viewpoint is disproven; Scientist 2's viewpoint is disproven
Scientist 1's viewpoint is disproven; Scientist 2's viewpoint is supported
Experiment A acts as a control to show the circuit setup works. Experiment B shows that the light bulb lights up when there is only a flow of electrons. In other words the flow of electrons are responsible for the flow of electricity, which supports Scientist 2's viewpoint. Experiment C allows for the flow of only protons and the light bulb does not turn on. This shows that the protons are not responsible for the flow of electricity and disproves Scientist 1's viewpoint.
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