Quantum and particle physics and relativity
Select all statements that are true regarding relativistic momentum. Multiple select question. Its minimum magnitude is zero. It is a scalar. It has the same dimensions as relativistic energy. It is a vector.
Its minimum magnitude is zero. It is a vector.
Select the correct equation for relativistic kinetic energy. Multiple choice question. K = (γ−1)γ-1mc2 K = (1/2)mv2 K = mc2 K = γmc2
K = (γ−1)γ-1mc2
According to the principle of relativity, which statement is true? Multiple choice question. The laws of physics are the same in all reference frames. The laws of physics are the same in all inertial reference frames. Measurements made by observers in all inertial reference frames are always the same. Measurements made by observers in all reference frames are always the same.
The laws of physics are the same in all inertial reference frames.
A particle of mass m moves at speed 0.00600c. What is the magnitude of its momentum? Multiple choice question. 0.00800mc 0.00750mc 0.00600mc
0.00600mc
Particle A of mass m is initially at rest. At a later time, it decays into two less massive particles, B and C. The masses of B and C are each 0.250m. B and C move at the same speed in opposite directions. Ignore potential energy in this problem. What is the kinetic energy of B? Multiple choice question. 0.500mc2 0.250mc2 0.750mc2 mc2
0.250mc2
A particle of mass 0.300 eV/c2 has a momentum of magnitude 0.400 eV/c. How much energy does the particle have? Multiple choice question. 0.700 eV 0.500 eV 0.120 eV
0.500 eV
A particle of mass m moves at speed 0.600c. What is the magnitude of its momentum? Multiple choice question. mc 0.800mc 0.600mc 0.750mc
0.750mc
A particle of mass 0.600 eV/c2 has a momentum of magnitude 0.800 eV/c. How much energy does it have? Multiple choice question. 0.480 eV 1.00 eV 1.40 eV
1.00 eV
A spaceship is located near a spaceport that is an inertial reference frame. In the spaceport frame, when the spaceship is at rest, it is 2.00 km long. In the spaceport frame, how long is the spaceship when it is moving at 0.866c in a direction that is parallel to its length? Multiple choice question. 1.00 km
1.00 km
A particle of mass 0.600 eV/c2 has a momentum of magnitude 0.800 eV/c. How much energy does it have? Multiple choice question. 1.40 eV 0.480 eV 1.00 eV
1.00eV
For massless particles, if the magnitude of the momentum doubles, then by what factor does the energy increase? Multiple choice question. 4 1.41 2
2
Levi is 2 m tall, stands on the Earth and with his telescope observes a meterstick hurtling through space to his right at a speed of 0.9c. The length of the meterstick is parallel to its velocity. A termite on the meterstick waves at him. How tall is Levi according to the termite? Multiple choice question. 2 m Greater than 2 m Less than 2 m
2 m
A spaceship is located near a spaceport that is an inertial reference frame. In the spaceport frame, when the spaceship is at rest, it is 2.00 km long. In the spaceport frame, how long is the spaceship when it is moving at 0.866c in a direction that is perpendicular to its length? Multiple choice question. 4.00 km 1.00 km 2.00 km
2.00 km
A new particle is produced in a laboratory that is an inertial reference frame. In the laboratory frame, when the new particle is at rest, it exists for only 2.00 s before it decays and breaks up into two smaller particles. In the laboratory frame, how long does the new particle exist before it decays when it is moving at 2250 m/s? Multiple choice question. 4.00 s 2.00 s 1.00 s
2.00 s
For massless particles, if the energy triples, then by what factor does the magnitude of the momentum increase? Multiple choice question. 9 1.73 3
3
According to Einstein's theory of special relativity, how many spacetime coordinates are required to specify an event? Multiple choice question. 1 3 4 2
4
A new particle is produced in a laboratory that is an inertial reference frame. In the laboratory frame, when the new particle is at rest, it exists for only 2.00 s before it decays and breaks up into two smaller particles. In the laboratory frame, how long does the new particle exist before it decays when it is moving at 0.866c? Multiple choice question. 4.00 s 1.00 s 2.00 s
4.00 s
Observer A and observer B are both in inertial reference frames. However, their reference frames are not the same. They both observe events 1 and 2. Select all of the following statements that are always true.
According to observer A, event 1 causes event 2. Therefore, according to observer B, event 1 causes event 2. According to observer A, event 2 causes event 1. Therefore, according to observer B, event 2 causes event 1.
What is an inertial reference frame? Multiple choice question. It is a reference frame in which an object accelerates only when no external net force acts upon it. It is a reference frame in which an object accelerates only when a net external force acts upon it. It is a reference frame in which an object remains at a constant velocity when a net external force acts upon it.
It is a reference frame in which an object accelerates only when a net external force acts upon it.
What is an inertial reference frame? Multiple choice question. It is a reference frame in which an object accelerates only when no external net force acts upon it. It is a reference frame in which an object remains at a constant velocity when a net external force acts upon it. It is a reference frame in which an object accelerates only when a net external force acts upon it.
It is a reference frame in which an object accelerates only when a net external force acts upon it.
What happens to the rest energy of an electron as it accelerates? Multiple choice question. It remains the same. It increases until the electron moves at the speed of light. It decreases until the electron moves at the speed of light.
It remains the same.
Select all statements that are true regarding relativistic momentum. Multiple select question. It is a scalar. It has the same dimensions as relativistic energy. Its minimum magnitude is zero. It is a vector.
Its minimum magnitude is zero. It is a vector.
Select all of the following quantities that can be used to determine if a particle is non-relativistic. Assume that the mass of the particle is known. Kinetic energy Acceleration magnitude Momentum magnitude Speed
Kinetic energy Momentum magnitude Speed
The total relativistic energy of an individual particle is equal to the sum of which two quantities? Multiple choice question. Kinetic energy and momentum Kinetic energy and potential energy Kinetic energy and rest energy Rest energy and potential energy
Kinetic energy and rest energy
The total relativistic energy of an individual particle is equal to the sum of which two quantities? Multiple choice question. Kinetic energy and rest energy Kinetic energy and momentum Rest energy and potential energy Kinetic energy and potential energy
Kinetic energy and rest energy
Match the quantities on the left with their properties on the right. Mass Distance Energy invariant neither invariant nor conserved conserved
Mass matches Invariant Distance matches Neither invariant nor conserved Energy matches Conserved
Select all of the following that require a medium to propagate. Multiple select question. Mechanical waves Sound waves Electromagnetic waves
Mechanical waves Sound waves
During a battle in space, a spaceship explodes in a brilliant flash of light that lasts 1 ms. Observer A is located on a planet 6 light-years from the battle. Observer B is located on another planet 1000 light-years from the battle. Both observers are located in inertial reference frames, and both see the light from the explosion. Select all of the following statements that are true. Multiple select question. Observer B sees the light before observer A does. Observer A sees the light before observer B does. Both observers are accelerating. Both observers measure the light moving at the same speed.
Observer A sees the light before observer B does. Both observers measure the light moving at the same speed.
Levi stands on the Earth and with his telescope observes a meterstick hurtling through space at a speed of 0.9c. The length of the meterstick is parallel to its velocity. A termite on the meterstick waves at him. How long is the meterstick according to the termite?
One meter
Levi stands on the Earth and with his telescope observes a meterstick hurtling through space at a speed of 0.9c. The length of the meterstick is parallel to its velocity. A termite on the meterstick waves at him. How long is the meterstick according to the termite? Multiple choice question. Less than one meter Greater than one meter One meter
One meter
Select all of the following particles that are nonrelativistic. Multiple select question. Particle at rest Particle of mass m with a momentum magnitude of mc Particle moving at c Particle of mass m with a kinetic energy of mc2 Particle moving at 5500 m/s
Particle at rest Particle moving at 5500 m/s
Select all of the following that are inertial reference frames. Multiple select question. Ballistic missile moving along a parabolic trajectory with respect to an inertial reference frame Spacecraft moving at a constant speed of half the speed of light in a circular orbit around the sun with respect to an inertial reference frame Spacecraft moving at a constant speed of half the speed of light along a straight line with respect to an inertial reference frame Spacecraft at rest with respect to an inertial reference frame Funny car accelerating at 5g along a straight line with respect to an inertial reference frame
Spacecraft moving at a constant speed of half the speed of light along a straight line with respect to an inertial reference frame Spacecraft at rest with respect to an inertial reference frame
Select all of the following that are inertial reference frames. Multiple select question. Spacecraft moving at a constant speed of half the speed of light along a straight line with respect to an inertial reference frame Funny car accelerating at 5g along a straight line with respect to an inertial reference frame Spacecraft at rest with respect to an inertial reference frame Spacecraft moving at a constant speed of half the speed of light in a circular orbit around the sun with respect to an inertial reference frame Ballistic missile moving along a parabolic trajectory with respect to an inertial reference frame
Spacecraft moving at a constant speed of half the speed of light along a straight line with respect to an inertial reference frame Spacecraft at rest with respect to an inertial reference frame
Select the two postulates upon which Einstein's theory of special relativity is based. Multiple select question. The laws of physics are the same in every inertial reference frame, independent of the motion of the reference frame. The laws of physics are the same in every noninertial reference frame, independent of the motion of the reference frame. The speed of light in vacuum varies according to the speed of the noninertial reference frame. The speed of light in vacuum is the same in every inertial reference frame.
The laws of physics are the same in every inertial reference frame, independent of the motion of the reference frame. The speed of light in vacuum is the same in every inertial reference frame.
According to an observer on the Earth, two spaceships are traveling at the same speed in opposite directions and are on a head-on collision course. Each spaceship moves at 0.9c, according to observers on the other spaceship. What would the observer on the Earth measure as the speed of each ship relative to the Earth? Multiple choice question. The relative speed is less than 0.45c. The relative speed is equal to 0.45c. The relative speed is greater than 0.45c.
The relative speed is greater than 0.45c.
According to an observer on the Earth, two spaceships traveling in opposite directions are on a head-on collision course. They both move at 0.9c, according to the observer on the Earth. What would an observer on one of the ships measure as the relative speed of the other ship? Multiple choice question. The relative speed is greater than the speed of light. The relative speed is less than 0.9c. The relative speed is greater than 0.9c but less than the speed of light.
The relative speed is greater than 0.9c but less than the speed of light.
Select all of the following that are true regarding rest energy and mass. Multiple select question. They are directly proportional. They are only equal when the object is at rest. They are both vectors. They are only equal when the object moves at the speed of light. They are both scalars. They are inversely proportional.
They are directly proportional. They are both scalars.
Select all that apply Observer A and observer B are both at rest in inertial reference frames. However, their reference frames move with respect to each other. They both observe system S. Select all of the following statements that are always true. Multiple select question. They both conclude that the momentum of system S is conserved. They both measure the same momentum of system S. They both measure the same energy of system S. They both conclude that the energy of system S is conserved.
They both conclude that the momentum of system S is conserved. They both conclude that the energy of system S is conserved.
When is relativistic momentum approximately equal to nonrelativistic momentum? Multiple choice question. Always When the speed of the object is very large compared to the speed of light When the speed of the object is very small compared to the speed of light Never When the speed of the object is equal to the speed of light
When the speed of the object is very small compared to the speed of light
When is relativistic momentum approximately equal to nonrelativistic momentum? Multiple choice question. When the speed of the object is equal to the speed of light When the speed of the object is very large compared to the speed of light When the speed of the object is very small compared to the speed of light Never Always
When the speed of the object is very small compared to the speed of light
Select all of the following that are units commonly used in particle physics. Multiple select question. eV kg J eV/c2
eV eV/c2
Match the unit commonly used in particle physics on the left with the quantity on the right. eV eV/c eV/c2 Energy Momentum mass
eV=Energy eV/c=Momentum eV/c2=mass
Levi stands on the Earth and with his telescope observes a meterstick hurtling through space at a speed of 0.9c. The length of the meterstick is parallel to its velocity. How long is the meterstick according to Levi?
less than one meter
Match the quantities on the left with their properties on the right. The speed of light Acceleration Momentum Invariant Conserved Neither invariant nor conserved
the speed of light=Invariant acceleration=Neither invariant nor conserved momentum=Conserved
Time dilation means that Δt = γΔt0. Assuming that v is less than c, which will be larger, Δt or Δt0?
Δt
Hannah is on Earth and stops her stopwatch after 30 seconds. David flies overhead in a rapidly moving spaceship and observes Hannah's stopwatch count up to 30 seconds. Does Hannah measure Δt or Δt0? Multiple choice question. Δt Δt0
Δt0
Time dilation means that Δt = γΔt0. Which is the proper time, Δt or Δt0? Multiple choice question. Δt0
Δt0
Which statement is true? Multiple choice question. Both Galilean relativity and Special relativity are approximations. Galilean relativity is an approximation. Neither Galilean relativity nor Special relativity are approximations. Special relativity is an approximation.
Galilean relativity is an approximation.
Hannah is on Earth and stops her stopwatch after 30 seconds. David flies overhead in a rapidly moving spaceship and observes Hannah's stopwatch count up to 30 seconds. How much time will David say elapsed according to the clock in his ship? Multiple choice question. Greater than 30 seconds Less than 30 seconds 30 seconds
Greater than 30 seconds
When is the principle of relativity applicable? Multiple choice question. Never When the mass of the system is constant In noninertial reference frames only In inertial reference frames only When the energy of the system is constant Always When the momentum of the system is constant
In inertial reference frames only
What is an inertial reference frame? Multiple choice question. It is a reference frame in which an object accelerates only when a net external force acts upon it. It is a reference frame in which an object accelerates only when no external net force acts upon it. incorrect Reason: In an inertial reference frame, an object remains at a constant velocity unless acted upon by a net external force. It is a reference frame in which an object remains at a constant velocity when a net external force acts upon it. Reason: In an inertial reference frame, an object remains at a constant velocity unless acted upon by a net external force.
It is a reference frame in which an object accelerates only when a net external force acts upon it.
Observer A and observer B are both in inertial reference frames. However, their reference frames are not the same. They both observe events 1 and 2. Select all of the following statements that are always true. Multiple select question. According to observer A, event 2 causes event 1. Therefore, according to observer B, event 2 causes event 1. According to observer A, event 1 causes event 2. Therefore, according to observer B, event 1 causes event 2. According to observer A, event 2 causes event 1. Therefore, according to observer B, event 1 causes event 2. According to observer A, event 1 causes event 2. Therefore, according to observer B, event 2 causes event 1.
According to observer A, event 2 causes event 1. Therefore, according to observer B, event 2 causes event 1. According to observer A, event 1 causes event 2. Therefore, according to observer B, event 1 causes event 2.
For which observers does the cause come before the effect? Multiple choice question. All observers in inertial reference frames Only observers in the reference frame in which both the cause and effect occur Only observers in the reference frame in which the cause occurs Only observers in the reference frame in which the effect occurs
All observers in inertial reference frames
For which observers does the cause come before the effect? Multiple choice question. Only observers in the reference frame in which both the cause and effect occur Only observers in the reference frame in which the cause occurs All observers in inertial reference frames Only observers in the reference frame in which the effect occurs
All observers in inertial reference frames
For which observers does the cause come before the effect? Multiple choice question. Only observers in the reference frame in which the cause occurs All observers in inertial reference frames Only observers in the reference frame in which both the cause and effect occur Only observers in the reference frame in which the effect occurs
All observers in inertial reference frames
Select all of the following statements that are true of Galilean relativity and Einsteinian relativity. Multiple select question. Einsteinian relativity is valid for all speeds less than or equal to c. Einsteinian relativity is valid only for speeds small compared to c. Galilean relativity is valid only for speeds that are small compared to c. Galilean relativity is valid for all speeds less than or equal to c.
Einsteinian relativity is valid for all speeds less than or equal to c. Galilean relativity is valid only for speeds that are small compared to c.
What was the medium in which nineteenth-century scientists believed light propagated? Multiple choice question. Air Vacuum Ether
Ether
