All ACT Science Resources
Example Questions
Example Question #967 : Act Science
Two physics students are describing a concept called the orbital radius.
Student 1: Orbital radius is defined as the distance from an object in orbit to the object that is being orbited. For example, this would include the distance from a satellite orbiting Earth to the Earth. Several factors affect an orbiting object's orbital radius. The mass of the object compared to the object being orbited, the speed at which the orbiting object is moving, and the gravitational force pulling at the orbiting object.
Student 2: An orbital radius is the distance from an orbiting object's center to the center of the object being orbited. The only thing that affects an orbiting object's orbital radius is the object's speed. A faster orbiting object will have a lower orbital radius and vice versa.Â
Jupiter has 67 moons orbiting it. When studying why these moons never collide, it is revealed that all 67 of jupiter's moons have different orbital radii. What would the students say about their speeds?
Student 1: Jupiter's moons must have the same speed.
Student 2: Jupiter's moons may have the same speed.
Student 1: Jupiter's moons may have different speeds.
Student 2: Jupiter's moons must have different speeds.
Student 1: Jupiter's moons may have the same speeds.
Student 2: Jupiter's moons may have different speeds.
Student 1: More information is necessary.
Student 2: More information is necessary.
Student 1: Jupiter's moons must have different speeds.
Student 2: Jupiter's moons may have different speeds.
Student 1: Jupiter's moons may have different speeds.
Student 2: Jupiter's moons must have different speeds.
The correct answer is that Student 1 would say that the speeds may vary while Student 2 would have to argue that they are all different. For Student 2, orbital radius is the end-all-be-all for orbital speed. That is, if objects have different orbital radii, they must also have different speeds. On the other hand, Student 1 points to various factors—mass and speed—affecting orbital radius. Since mass is not clarified in the question, Student 1 would not be able to definitively speak to the orbital speeds of the moons; therefore, Student 1 is most likely to give a a non-definitive answer like Student 2's answer.
Example Question #961 : Act Science
Two physics students are describing a concept called the orbital radius.
Student 1: Orbital radius is defined as the distance from an object in orbit to the object that is being orbited. For example, this would include the distance from a satellite orbiting Earth to the Earth. Several factors affect an orbiting object's orbital radius. The mass of the object compared to the object being orbited, the speed at which the orbiting object is moving, and the gravitational force pulling at the orbiting object.
Student 2: An orbital radius is the distance from an orbiting object's center to the center of the object being orbited. The only thing that affects an orbiting object's orbital radius is the object's speed. A faster orbiting object will have a lower orbital radius and vice versa.Â
It is found that all 67 of Jupiter's moons have different masses and different orbital radii. How does this new information affect each student's claims?
It supports the claims of both student 1 and student 2.
It supports the claims of student 1 but refutes the claims of student 2.
It supports the claims of student 2 but refutes the claims of student 1.
It refutes the claims of both student 1 and student 2.
More information is necessary.
It supports the claims of both student 1 and student 2.
The correct answer is that it supports both claims. While it might more clearly support Student 1's claims that differences in masses affect orbital radii, this information does not tell us whether there is some sort of relationship between any of the variables involved. All it says is that objects with varying masses and speeds also have varying orbital radii. This could support both students since Student 2 might argue that the differences in orbital radii are only due to their differences in speed and not mass.
Example Question #969 : Act Science
Two physics students are describing a concept called the orbital radius.
Student 1: Orbital radius is defined as the distance from an object in orbit to the object that is being orbited. For example, this would include the distance from a satellite orbiting Earth to the Earth. Several factors affect an orbiting object's orbital radius. The mass of the object compared to the object being orbited, the speed at which the orbiting object is moving, and the gravitational force pulling at the orbiting object.
Student 2: An orbital radius is the distance from an orbiting object's center to the center of the object being orbited. The only thing that affects an orbiting object's orbital radius is the object's speed. A faster orbiting object will have a lower orbital radius and vice versa.Â
Two satellites, one very small and one very large, are in orbit around the Earth in what is called geostationary orbit. Geostationary orbit is a precise distance from the Earth where many commercial satelites are sent. The two satellites are found to have the exact same orbital speed. How does this new information affect the students' claims?
More information is needed to draw a conclusion on their claims.
This information supports the claims of both students.
This information refutes the claims of Student 2 and supports the claims of Student 1.
This information supports the claims of Student 2 and refutes the claims of Student 1.
This information refutes the claims of both students.
This information supports the claims of Student 2 and refutes the claims of Student 1.
The correct answer is that it supports student 2 and refutes student 1. Since the satellites have different masses and identical speeds, Student 1 would argue that they should have different orbital radii. But since both are in geostationary orbit, we know that this is not the case. Student 2, however, would agree with this, since Student 2 made a point that orbital speed is the only thing that affects orbital radius.Â
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It should be noted that this is only partially true. The only two factors that affect orbital radius are orbital speed and the mass of the object being orbited. Both students were partially correct.
Example Question #970 : Act Science
Glaciers move, on average, 1 meter per day, although many are known to move faster or slower depending on their size. Whether they are alpine glaciers, which form high in the mountains, or continental glaciers that cover huge areas of land near the poles, glaciers are responsible for breaking up rock and moving sediment as they move across the land.Â
Below is a chart of average speed of movement of an alpine glacier per year, as well the amount of sediment displaced by the glacier.Â
Year |
Average Glacial Movement |
Sediment movement per year (tons) |
1995 |
1.1 m/day |
2.2 |
1996 |
1.3 m/day |
2.6 |
1997 |
1.5 m/day |
3.0 |
1998 |
1.3 m/day |
2.2 |
2000 |
1.1 m/day |
1.8 |
2005 |
1.0 m/day |
1.6 |
2010 |
0.9 m/day |
1.5 |
Two scientists have done research on an alpine lake that lies in the path of the glacier. Each took five samples of sediment from the lake.
Scientist 1 believes that the glacier is beginning to melt as it moves lower in elevation, releasing some of the sediment it has carried into mountain streams and springs, causing the makeup of sediments in the lake to change. He notes that the sediment from the lake bed contains brown chert, a rock that can only be found in elevations higher than that of the lake. Scientist 1 took his sample from the sediments that washed ashore on the beach of the lake.
Scientist 2Â believes the glacier is not melting, but displacing rock beds so that the sediment loosens and breaks free of the bedrock and then is carried by wind and other erosive elements to the lake. He notes that the sediment from the lake bed contains only trace amounts of the brown chert, not enough to suggest the glacier is melting. Scientist 2 took his samples from sediment deposits at the bottom of the lake.Â
Below is a chart of the sediment collection samples and the percentage of brown chert found in each.
Sample # |
Scientist 1: % Brown Chert |
Scientist 2: % Brown Chert |
1 |
5.2 |
0.9 |
2 |
7.1 |
1.2 |
3 |
6.3 |
0.4 |
4 |
6.5 |
0.8 |
5 |
5.8 |
1.0 |
Â
Which of the following findings would most closely resemble the hypothesis of scientist 1?Â
The alpine lake below the glacier is lower in water volume than it has been in the last decade.
The alpine lake below the glacier only has one kind of fish.
Sediments containing the rock, brown chert, have been found as far as ten miles from the glacier.
Alpine springs in the area around the glacier have had a higher volume of water in the last five years.
None of the other answers is correct.
Alpine springs in the area around the glacier have had a higher volume of water in the last five years.
If the glacier is melting, like scientist 1 believes, there will be more water saturating the earth that would run into mountain springs, increasing their volume.Â
Example Question #31 : How To Find Conflicting Viewpoints In Earth And Space Sciences
Glaciers move, on average, 1 meter per day, although many are known to move faster or slower depending on their size. Whether they are alpine glaciers, which form high in the mountains, or continental glaciers that cover huge areas of land near the poles, glaciers are responsible for breaking up rock and moving sediment as they move across the land.Â
Below is a chart of average speed of movement of an alpine glacier per year, as well the amount of sediment displaced by the glacier.Â
Year |
Average Glacial Movement |
Sediment movement per year (tons) |
1995 |
1.1 m/day |
2.2 |
1996 |
1.3 m/day |
2.6 |
1997 |
1.5 m/day |
3.0 |
1998 |
1.3 m/day |
2.2 |
2000 |
1.1 m/day |
1.8 |
2005 |
1.0 m/day |
1.6 |
2010 |
0.9 m/day |
1.5 |
Two scientists have done research on an alpine lake that lies in the path of the glacier. Each took five samples of sediment from the lake.
Scientist 1 believes that the glacier is beginning to melt as it moves lower in elevation, releasing some of the sediment it has carried into mountain streams and springs, causing the makeup of sediments in the lake to change. He notes that the sediment from the lake bed contains brown chert, a rock that can only be found in elevations higher than that of the lake. Scientist 1 took his sample from the sediments that washed ashore on the beach of the lake.
Scientist 2Â believes the glacier is not melting, but displacing rock beds so that the sediment loosens and breaks free of the bedrock and then is carried by wind and other erosive elements to the lake. He notes that the sediment from the lake bed contains only trace amounts of the brown chert, not enough to suggest the glacier is melting. Scientist 2 took his samples from sediment deposits at the bottom of the lake.Â
Below is a chart of the sediment collection samples and the percentage of brown chert found in each.
Sample # |
Scientist 1: % Brown Chert |
Scientist 2: % Brown Chert |
1 |
5.2 |
0.9 |
2 |
7.1 |
1.2 |
3 |
6.3 |
0.4 |
4 |
6.5 |
0.8 |
5 |
5.8 |
1.0 |
Â
Which of the following findings would best support the hypothesis of Scientist 2?
The mountains on either side of the glacier have seen little in the way of foliage growth in the last decade.
The alpine lake is known to be hostile to animal life.
None of the other answers is correct.Â
Valleys formed in the wake of the glacier's movement have contained brown chert.
Weather patterns in the area have been particularly volatile in the last decade.
Weather patterns in the area have been particularly volatile in the last decade.
In order for Scientist 2's hypothesis to be correct, there would have to be an increase in the erosive elements that could carry the sediment displaced by the glacier. Volatile weather patterns, like increased wind and rain, would account for an increase in erosion.Â
Example Question #32 : How To Find Conflicting Viewpoints In Earth And Space Sciences
Glaciers move, on average, 1 meter per day, although many are known to move faster or slower depending on their size. Whether they are alpine glaciers, which form high in the mountains, or continental glaciers that cover huge areas of land near the poles, glaciers are responsible for breaking up rock and moving sediment as they move across the land.Â
Below is a chart of average speed of movement of an alpine glacier per year, as well the amount of sediment displaced by the glacier.Â
Year |
Average Glacial Movement |
Sediment movement per year (tons) |
1995 |
1.1 m/day |
2.2 |
1996 |
1.3 m/day |
2.6 |
1997 |
1.5 m/day |
3.0 |
1998 |
1.3 m/day |
2.2 |
2000 |
1.1 m/day |
1.8 |
2005 |
1.0 m/day |
1.6 |
2010 |
0.9 m/day |
1.5 |
Two scientists have done research on an alpine lake that lies in the path of the glacier. Each took five samples of sediment from the lake.
Scientist 1 believes that the glacier is beginning to melt as it moves lower in elevation, releasing some of the sediment it has carried into mountain streams and springs, causing the makeup of sediments in the lake to change. He notes that the sediment from the lake bed contains brown chert, a rock that can only be found in elevations higher than that of the lake. Scientist 1 took his sample from the sediments that washed ashore on the beach of the lake.
Scientist 2Â believes the glacier is not melting, but displacing rock beds so that the sediment loosens and breaks free of the bedrock and then is carried by wind and other erosive elements to the lake. He notes that the sediment from the lake bed contains only trace amounts of the brown chert, not enough to suggest the glacier is melting. Scientist 2 took his samples from sediment deposits at the bottom of the lake.Â
Below is a chart of the sediment collection samples and the percentage of brown chert found in each.
Sample # |
Scientist 1: % Brown Chert |
Scientist 2: % Brown Chert |
1 |
5.2 |
0.9 |
2 |
7.1 |
1.2 |
3 |
6.3 |
0.4 |
4 |
6.5 |
0.8 |
5 |
5.8 |
1.0 |
Â
Could scientists 1 and 2 agree on anything concerning the glacier?
Yes, both could agree the glacier will reach the lake before the year 2020.
Yes, both could agree that the sediment containing brown chert comes from the glacier.
Yes, both could agree the glacier is what's causing the alpine lake to be void of life.Â
No, they cannot agree.Â
Yes, both could agree the brown chert was carried by the glacier for at least a decade before being deposited in the lake.
Yes, both could agree that the sediment containing brown chert comes from the glacier.
The only reasonable answer is that the brown chert comes from the glacier. All other answers would require inference based on information that cannot be found in the question. They can at least agree that the only way for the sediment containing brown chert, which can only naturally be found in places higher than the lake, to be found in the lake itself is for the glacier to have moved it.
Example Question #31 : Earth And Space Sciences
Earth’s moon rotates like a satellite around Earth. It is the fifth largest moon in the Solar System and is best seen at night. The Earth’s moon is about 384,400 km from Earth and has an orbital period of twenty-seven days. Most scientists agree that the Moon formed about 4.5 billion years ago; however, there are several conflicting theories on the moon’s origin. Below two scientists discuss what they believe to be true.
Â
Scientist 1Â
The Fission Theory states that the Moon and Earth were once the same formation. A part of the formation separated from Earth and became the moon. The formation that broke off to form the moon most likely came from the Pacific Ocean Basin. The rock densities of the moon are similar to the rock densities of the Earth’s mantle. This is because the part that broke off from the Earth to form the moon broke off from the outer part of the Earth’s mantle. The theory that the Moon and Earth formed separately is highly unlikely. For this theory to be true, Earth’s gravitational field would have had to pull the moon into orbit. This is unlikely because it would have required a very particular set up. Most objects that come into the Earth’s gravitational field have elliptical orbits. If the Moon was pulled into orbit with the Earth, it would have a comet-like elliptical orbit—which it does not.
Â
Scientist 2
The Impactor Theory states that a small planet collided with the Earth just after the solar system was formed. This caused large amounts of materials from the outer shell of both planets to break off. This debris started orbiting the Earth and forming one collective body of material. That collective piece is what we now call the moon. The lunar rocks studied are burnt, implying they were heated at one time. This would make sense because when the small planet and Earth collide, the material became heated due to impact. In addition, the Moon does not have a magnetic field like Earth, but some of the rocks on the surface of the Moon hint the Moon could have had some sort of magnetic qualities at one time. This is because the Moon was partially made up of Earth’s outer rocks.
Which of the following best states the basis for the belief of Scientist 1?
The Moon was formed from a broken off piece of the Earth's mantle.Â
The Moon has the exact same rock composition as the Earth.
The Moon chipped off from the Earth, and was then pulled into Earth's orbit.Â
The Moon was pulled into orbit with the Earth
The Moon was formed from the fission of another planet.
The Moon was formed from a broken off piece of the Earth's mantle.Â
Scientist 1 believes that "a part of the formation separated from Earth and became the moon." Further, this piece was taken from the Earth's mantle as discussed in the sentence "the rock densities of the moon are similar to the rock densities of the Earth’s mantle."
Example Question #32 : Earth And Space Sciences
Earth’s moon rotates like a satellite around Earth. It is the fifth largest moon in the Solar System and is best seen at night. The Earth’s moon is about 384,400 km from Earth and has an orbital period of twenty-seven days. Most scientists agree that the Moon formed about 4.5 billion years ago; however, there are several conflicting theories on the moon’s origin. Below two scientists discuss what they believe to be true.
Â
Scientist 1Â
The Fission Theory states that the Moon and Earth were once the same formation. A part of the formation separated from Earth and became the moon. The formation that broke off to form the moon most likely came from the Pacific Ocean Basin. The rock densities of the moon are similar to the rock densities of the Earth’s mantle. This is because the part that broke off from the Earth to form the moon broke off from the outer part of the Earth’s mantle. The theory that the Moon and Earth formed separately is highly unlikely. For this theory to be true, Earth’s gravitational field would have had to pull the moon into orbit. This is unlikely because it would have required a very particular set up. Most objects that come into the Earth’s gravitational field have elliptical orbits. If the Moon was pulled into orbit with the Earth, it would have a comet-like elliptical orbit—which it does not.
Â
Scientist 2
The Impactor Theory states that a small planet collided with the Earth just after the solar system was formed. This caused large amounts of materials from the outer shell of both planets to break off. This debris started orbiting the Earth and forming one collective body of material. That collective piece is what we now call the moon. The lunar rocks studied are burnt, implying they were heated at one time. This would make sense because when the small planet and Earth collide, the material became heated due to impact. In addition, the Moon does not have a magnetic field like Earth, but some of the rocks on the surface of the Moon hint the Moon could have had some sort of magnetic qualities at one time. This is because the Moon was partially made up of Earth’s outer rocks.
When it comes to the Moon, both scientists agree that __________.
the Moon orbits around the Earth
the Moon takes twenty seven days to orbit Earth
none of the answer choices are correct
the Moon was formed about 4.5 billion years ago
all of the answer choices (except "none") are correct
all of the answer choices (except "none") are correct
Most of the answer choices list information that is factual stated in the first paragraph. "The Moon orbits around the Earth" is a piece of information that can be inferred to be true after reading both scientist's beliefs.Â
Example Question #31 : Earth And Space Sciences
Earth’s moon rotates like a satellite around Earth. It is the fifth largest moon in the Solar System and is best seen at night. The Earth’s moon is about 384,400 km from Earth and has an orbital period of twenty-seven days. Most scientists agree that the Moon formed about 4.5 billion years ago; however, there are several conflicting theories on the moon’s origin. Below two scientists discuss what they believe to be true.
Â
Scientist 1Â
The Fission Theory states that the Moon and Earth were once the same formation. A part of the formation separated from Earth and became the moon. The formation that broke off to form the moon most likely came from the Pacific Ocean Basin. The rock densities of the moon are similar to the rock densities of the Earth’s mantle. This is because the part that broke off from the Earth to form the moon broke off from the outer part of the Earth’s mantle. The theory that the Moon and Earth formed separately is highly unlikely. For this theory to be true, Earth’s gravitational field would have had to pull the moon into orbit. This is unlikely because it would have required a very particular set up. Most objects that come into the Earth’s gravitational field have elliptical orbits. If the Moon was pulled into orbit with the Earth, it would have a comet-like elliptical orbit—which it does not.
Â
Scientist 2
The Impactor Theory states that a small planet collided with the Earth just after the solar system was formed. This caused large amounts of materials from the outer shell of both planets to break off. This debris started orbiting the Earth and forming one collective body of material. That collective piece is what we now call the moon. The lunar rocks studied are burnt, implying they were heated at one time. This would make sense because when the small planet and Earth collide, the material became heated due to impact. In addition, the Moon does not have a magnetic field like Earth, but some of the rocks on the surface of the Moon hint the Moon could have had some sort of magnetic qualities at one time. This is because the Moon was partially made up of Earth’s outer rocks.
Scientist 2 uses what piece of detail to support his overall viewpoint?
Most objects that come into the Earth’s gravitational field have elliptical orbits.
It is the fifth largest moon in the Solar System and is best seen at night.
The lunar rocks studied are burnt, implying they were heated at one time.
The formation that broke off to form the moon most likely came from the Pacific Ocean Basin.
The rock densities of the moon are similar to the rock densities of the Earth’s mantle.
The lunar rocks studied are burnt, implying they were heated at one time.
The fact that the lunar rocks are burnt is a detail discussed by Scientist 2 to support his viewpoint. All of the other options are details either discussed by Scientist 1 or stated in the first paragraph.
Example Question #32 : Earth And Space Sciences
Earth’s moon rotates like a satellite around Earth. It is the fifth largest moon in the Solar System and is best seen at night. The Earth’s moon is about 384,400 km from Earth and has an orbital period of twenty-seven days. Most scientists agree that the Moon formed about 4.5 billion years ago; however, there are several conflicting theories on the moon’s origin. Below two scientists discuss what they believe to be true.
Â
Scientist 1Â
The Fission Theory states that the Moon and Earth were once the same formation. A part of the formation separated from Earth and became the moon. The formation that broke off to form the moon most likely came from the Pacific Ocean Basin. The rock densities of the moon are similar to the rock densities of the Earth’s mantle. This is because the part that broke off from the Earth to form the moon broke off from the outer part of the Earth’s mantle. The theory that the Moon and Earth formed separately is highly unlikely. For this theory to be true, Earth’s gravitational field would have had to pull the moon into orbit. This is unlikely because it would have required a very particular set up. Most objects that come into the Earth’s gravitational field have elliptical orbits. If the Moon was pulled into orbit with the Earth, it would have a comet-like elliptical orbit—which it does not.
Â
Scientist 2
The Impactor Theory states that a small planet collided with the Earth just after the solar system was formed. This caused large amounts of materials from the outer shell of both planets to break off. This debris started orbiting the Earth and forming one collective body of material. That collective piece is what we now call the moon. The lunar rocks studied are burnt, implying they were heated at one time. This would make sense because when the small planet and Earth collide, the material became heated due to impact. In addition, the Moon does not have a magnetic field like Earth, but some of the rocks on the surface of the Moon hint the Moon could have had some sort of magnetic qualities at one time. This is because the Moon was partially made up of Earth’s outer rocks.
What is the main conflicting viewpoint between Scientist 1 or Scientist 2?
Scientist 1 believes the Moon was formed from debris pulled into Earth's orbit, while Scientist 2 believes the Moon was formed from pieces of the Earth as well as pieces of another planet.
Scientist 1 believes that the Moon is composed of material from Earth and Mars, while Scientist 2 believes the Moon is composed of material from just Earth.Â
Scientist 1 believes that the Moon formed from pieces of the Earth, while Scientist 2 believes the Moon was formed from pieces of the Earth as well as pieces of another planet.
Scientist 1 believes the Moon was formed from pieces of the Earth as well as pieces of another planet, while Scientist 2 believes that the Moon formed from pieces of the Earth.Â
Scientist 1 believes that the Moon formed from pieces of the Earth, while Scientist 2 believes the Moon was formed from the collision of two planets that orbited Earth.
Scientist 1 believes that the Moon formed from pieces of the Earth, while Scientist 2 believes the Moon was formed from pieces of the Earth as well as pieces of another planet.
After reading each Scientist's viewpoint, it is clear Scientist 1 believes the Moon was formed from just the Earth, while Scientist 2 states that the "collective piece" formed from the Earth and another planet created the Moon.
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