ACT Science › How to find research summary in physics
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 __________.
All particles are placed an equal distance from the test charge.
Particle A and particle D have equal sign and magnitude.
Particle A and particle B have equal sign and magnitude.
All particles have an equal charge density.
Subtract the position of the particle from the initial position of the test charge.
In each experiment the result is 8m.
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
?
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
.
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 __________.
All particles are placed an equal distance from the test charge.
Particle A and particle D have equal sign and magnitude.
Particle A and particle B have equal sign and magnitude.
All particles have an equal charge density.
Subtract the position of the particle from the initial position of the test charge.
In each experiment the result is 8m.
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
?
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
.
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?
Study 2, because using the same medium shows that velocity increases as density decreases
Study 2, because using the same medium shows that velocity decreases as density decreases
Study 1, because using different media shows that velocity increases as density decreases
Study 1, because using different media shows that velocity increases as density increases
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.
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?
Study 2, because using the same medium shows that velocity increases as density decreases
Study 2, because using the same medium shows that velocity decreases as density decreases
Study 1, because using different media shows that velocity increases as density decreases
Study 1, because using different media shows that velocity increases as density increases
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.
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?
Trial 2 only
Trials 2 and 3
Trial 3 only
Trials 1 and 2
By inspecting the table, we see that the time of flight changed between data points for Trial 2 only.
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?
Trial 2 only
Trials 2 and 3
Trial 3 only
Trials 1 and 2
By inspecting the table, we see that the time of flight changed between data points for Trial 2 only.
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.
Particle A has a higher magnitude of charge than particle B.
Particle A has the same magnitude of charge as particle B.
Particle A has a lower charge density than particle B.
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.
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.
Particle A has a higher magnitude of charge than particle B.
Particle A has the same magnitude of charge as particle B.
Particle A has a lower charge density than particle B.
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.