Question 1

An earthbound radar monitors a spaceship moving at 0.9c. The crew of this first ship monitors a second ship following them at 0.8c with respect to them. What is the speed of the second ship as recorded by the earthbound radar?

Accepted Answer

A)   0.988c
B)   0.180c
C)   0.850c
D)   0.367c
E)   1.70cF) B) and C)
G) A) and B) A

Question 2

An electron is accelerated from rest by a total potential difference of 2.00 × 108 V. Its mass at this energy is

Accepted Answer

A)   9.1 × 10-31 kg.
B)   2.27 × 10-33 kg.
C)   1.67 × 10-27 kg.
D)   3.58 × 10-28 kg.
E)   1.12 × 10-16 kg.F) A) and D)
G) B) and E) D

Question 3

An astronaut aboard a spacecraft en route to Mars with a speed of 0.5c relative to Earth observes a meteor approaching head on at a speed of 0.9c. What is the speed of the meteor relative to Earth?

Accepted Answer

A)   1.4c
B)   -0.73c
C)   0.4c
D)   2.55c
E)   None of these is correct.F) C) and D)
G) A) and B)

Question 4

Your strange friend flies past you in a relativistic spacecraft holding a meterstick and a clock. The meterstick appears too _____ to you, and the clock appears _____ to you.

Accepted Answer

A)   short; slow
B)   long; slow
C)   short; fast
D)   long; fast
E)   short; normalF) None of the above
G) D) and E) A

Question 5

The results of the Michelson-Morley experiment can be interpreted to indicate that if an ether exists,

Accepted Answer

A)   light waves and sound waves are the same.
B)   light waves and sound waves are not the same.
C)   the ether is dragged along by the experiment.
D)   the ether is not dragged along by the experiment.
E)   the speed of light in the ether is 3 × 108 m/s.F) A) and B)
G) A) and D)

Question 6

A spaceship travels at a speed of 0.95c to the nearest star, Alpha Centauri, 4.3 light years ly)  away. How long does the trip take from the point of view of the passengers on the ship?

Accepted Answer

A)   1.4 ly
B)   1.0 ly
C)   4.5 ly
D)   14 ly
E)   0.44 lyF) B) and D)
G) A) and D)

Question 7

While astronauts in a spaceship with a speed of 0.6c relative to Earth move outward from Earth toward Jupiter, they observe a cosmic ray shower that contains protons moving toward them. On Earth the speed of these protons is measured as 0.2c toward the spaceship. They measure the speed of the protons to be

Accepted Answer

A)   0.80c.
B)   0.71c.
C)   0.95c.
D)   0.69c.
E)   0.45c.F) A) and D)
G) B) and C)

Question 8

At rest, pions have a proper lifetime of 26 ns. What is the speed of a beam of pions if their observed lifetime were measured to be 64 ns ? This is a real experiment that has been performed and found to be consistent with special relativity.)

Accepted Answer

A)   0.96c
B)   0.84c
C)   0.70c
D)   0.41c
E)   0.91cF) None of the above
G) A) and C)

Question 9

4 kilotons of TNT. This is equivalent to 9.0 × 1026 MeV. The mass that was converted into energy in this explosion was

Accepted Answer

A)   1.6 kg.
B)   1.6 × 10-3 kg.
C)   1.4 × 1014 kg.
D)   1.1 × 1010 kg.
E)   120 kg.F) B) and C)
G) B) and E)

Question 10

What is the momentum of a photon having the same total energy as an electron with a kinetic energy of 100 keV?

Accepted Answer

A)   zero
B)   611 keV/c
C)   100 keV/c
D)   211 keV/c
E)   411 keV/cF) C) and D)
G) A) and E)

Question 11

Because the galaxies are moving away from us, the light they emit

Accepted Answer

A)   is shifted toward the shorter, blue wavelengths.
B)   is shifted toward the longer, red wavelengths.
C)   is of the same wavelength it would be if they were at rest relative to Earth.
D)   arrives with increased intensity.
E)   None of these is correct.F) None of the above
G) B) and E)

Question 12

The mass of an electron traveling at 0.8c is how many times as great as its rest mass?

Accepted Answer

A)   0.60
B)   0.78
C)   0.80
D)   1.28
E)   1.67F) A) and E)
G) All of the above

Question 13

The total yearly world consumption of energy is approximately 4.0 × 1020 J. How much mass would have to be completely converted into energy to provide this amount of energy?

Accepted Answer

A)   4.4 × 103 kg
B)   1.3 × 1012 kg
C)   1.3 × 104 kg
D)   4.4 × 105 kg
E)   2.2 × 104 kgF) C) and D)
G) A) and B)

Question 14

If one gram of matter could be completely converted into energy, the yield would be

Accepted Answer

A)   0.51 MeV.
B)   931 MeV.
C)   3 × 1013 J.
D)   9 × 1013 J.
E)   9 × 1016 J.F) None of the above
G) B) and C)

Question 15

The kinetic energy of an electron traveling at 0.98c is

Accepted Answer

A)   0.2452 MeV.
B)   0.5110 MeV.
C)   0.756 MeV.
D)   1.225 MeV.
E)   2.044 MeV.F) A) and E)
G) D) and E)

Question 16

Newton's laws cannot be used to describe the behavior of an object moving in an)

Accepted Answer

A)   inertial reference frame.
B)   accelerated reference frame.
C)   reference frame moving with constant velocity.
D)   reference frame that is stationary.
E)   None of the above.F) B) and D)
G) B) and E)

Question 17

A proton and an electron are accelerated until their total energy is twice their rest masses. If the rest mass of the proton is Mpc2 = 931 MeV and that of the electron is Mec2 = 0.51 MeV, the ratio of the velocity of the electron to that of the proton is

Accepted Answer

A)   0.5.
B)   1.0.
C)   1.5.
D)   2.0.
E)   Not enough data are given.F) C) and D)
G) B) and C)

Question 18

A pion lives 26 ns in its rest frame. It travels 15 cm down a beam pipe in a particle accelerator before it decays into other particles. How far is this in the rest frame of the pion?

Accepted Answer

A)   19.026 cm
B)   18.465 cm
C)   16.123 cm
D)   14.997 cm
E)   12.886 cmF) B) and E)
G) A) and D)

Question 19

You see a system consisting of a mass oscillating on the end of a spring passed you at a speed u and note that the period of the system is T. Your strange friend, who is moving with the mass-spring system, also measures its period and finds a period that is

Accepted Answer

A)   equal to T.
B)   less than T.
C)   greater than T.
D)   either a or b depending on whether the system was approaching or receding from the first observer.
E)   There is not sufficient information to answer the question.F) A) and B)
G) A) and E)

Question 20

The momentum of an electron moving at 0.8c is approximately

Accepted Answer

A)   0.511 MeV/c.
B)   1.02 MeV/c.
C)   2.18 × 10-22 kg · m/s.
D)   3.64 × 10-22 kg · m/s.
E)   5.82 × 10-22 kg · m/s.F) A) and B)
G) B) and D)

Exam 25: Relativity

An earthbound radar monitors a spaceship moving at 0.9c. The crew of this first ship monitors a second ship following them at 0.8c with respect to them. What is the speed of the second ship as recorded by the earthbound radar?

Correct Answer
verified
A

An electron is accelerated from rest by a total potential difference of 2.00 × 10⁸ V. Its mass at this energy is

Correct Answer
verified
D

An astronaut aboard a spacecraft en route to Mars with a speed of 0.5c relative to Earth observes a meteor approaching head on at a speed of 0.9c. What is the speed of the meteor relative to Earth?

Correct Answer
verified

Your strange friend flies past you in a relativistic spacecraft holding a meterstick and a clock. The meterstick appears too _ to you, and the clock appears _ to you.

Correct Answer
verified
A

The results of the Michelson-Morley experiment can be interpreted to indicate that if an ether exists,

Correct Answer
verified

A spaceship travels at a speed of 0.95c to the nearest star, Alpha Centauri, 4.3 light years ly) away. How long does the trip take from the point of view of the passengers on the ship?

Correct Answer
verified

Correct Answer
verified

At rest, pions have a proper lifetime of 26 ns. What is the speed of a beam of pions if their observed lifetime were measured to be 64 ns ? This is a real experiment that has been performed and found to be consistent with special relativity.)

Correct Answer
verified

4 kilotons of TNT. This is equivalent to 9.0 × 10²⁶ MeV. The mass that was converted into energy in this explosion was

Correct Answer
verified

What is the momentum of a photon having the same total energy as an electron with a kinetic energy of 100 keV?

Correct Answer
verified

Because the galaxies are moving away from us, the light they emit

Correct Answer
verified

The mass of an electron traveling at 0.8c is how many times as great as its rest mass?

Correct Answer
verified

The total yearly world consumption of energy is approximately 4.0 × 10²⁰ J. How much mass would have to be completely converted into energy to provide this amount of energy?

Correct Answer
verified

If one gram of matter could be completely converted into energy, the yield would be

Correct Answer
verified

The kinetic energy of an electron traveling at 0.98c is

Correct Answer
verified

Newton's laws cannot be used to describe the behavior of an object moving in an)

Correct Answer
verified

A proton and an electron are accelerated until their total energy is twice their rest masses. If the rest mass of the proton is M_pc² = 931 MeV and that of the electron is M_ec² = 0.51 MeV, the ratio of the velocity of the electron to that of the proton is

Correct Answer
verified

A pion lives 26 ns in its rest frame. It travels 15 cm down a beam pipe in a particle accelerator before it decays into other particles. How far is this in the rest frame of the pion?

Correct Answer
verified

You see a system consisting of a mass oscillating on the end of a spring passed you at a speed u and note that the period of the system is T. Your strange friend, who is moving with the mass-spring system, also measures its period and finds a period that is

Correct Answer
verified

The momentum of an electron moving at 0.8c is approximately

Correct Answer
verified

Exam 25: Relativity

An earthbound radar monitors a spaceship moving at 0.9c. The crew of this first ship monitors a second ship following them at 0.8c with respect to them. What is the speed of the second ship as recorded by the earthbound radar?

Correct AnswerverifiedA

An electron is accelerated from rest by a total potential difference of 2.00 × 108 V. Its mass at this energy is

Correct AnswerverifiedD

An astronaut aboard a spacecraft en route to Mars with a speed of 0.5c relative to Earth observes a meteor approaching head on at a speed of 0.9c. What is the speed of the meteor relative to Earth?

Correct AnswerverifiedShow Answer

Your strange friend flies past you in a relativistic spacecraft holding a meterstick and a clock. The meterstick appears too _____ to you, and the clock appears _____ to you.

Correct AnswerverifiedA

The results of the Michelson-Morley experiment can be interpreted to indicate that if an ether exists,

Correct AnswerverifiedShow Answer

A spaceship travels at a speed of 0.95c to the nearest star, Alpha Centauri, 4.3 light years ly) away. How long does the trip take from the point of view of the passengers on the ship?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

At rest, pions have a proper lifetime of 26 ns. What is the speed of a beam of pions if their observed lifetime were measured to be 64 ns ? This is a real experiment that has been performed and found to be consistent with special relativity.)

Correct AnswerverifiedShow Answer

4 kilotons of TNT. This is equivalent to 9.0 × 1026 MeV. The mass that was converted into energy in this explosion was

Correct AnswerverifiedShow Answer

What is the momentum of a photon having the same total energy as an electron with a kinetic energy of 100 keV?

Correct AnswerverifiedShow Answer

Because the galaxies are moving away from us, the light they emit

Correct AnswerverifiedShow Answer

The mass of an electron traveling at 0.8c is how many times as great as its rest mass?

Correct AnswerverifiedShow Answer

The total yearly world consumption of energy is approximately 4.0 × 1020 J. How much mass would have to be completely converted into energy to provide this amount of energy?

Correct AnswerverifiedShow Answer

If one gram of matter could be completely converted into energy, the yield would be

Correct AnswerverifiedShow Answer

The kinetic energy of an electron traveling at 0.98c is

Correct AnswerverifiedShow Answer

Newton's laws cannot be used to describe the behavior of an object moving in an)

Correct AnswerverifiedShow Answer

A proton and an electron are accelerated until their total energy is twice their rest masses. If the rest mass of the proton is Mpc2 = 931 MeV and that of the electron is Mec2 = 0.51 MeV, the ratio of the velocity of the electron to that of the proton is

Correct AnswerverifiedShow Answer

A pion lives 26 ns in its rest frame. It travels 15 cm down a beam pipe in a particle accelerator before it decays into other particles. How far is this in the rest frame of the pion?

Correct AnswerverifiedShow Answer

You see a system consisting of a mass oscillating on the end of a spring passed you at a speed u and note that the period of the system is T. Your strange friend, who is moving with the mass-spring system, also measures its period and finds a period that is

Correct AnswerverifiedShow Answer

The momentum of an electron moving at 0.8c is approximately

Correct AnswerverifiedShow Answer

Correct Answer
verified
A

An electron is accelerated from rest by a total potential difference of 2.00 × 10⁸ V. Its mass at this energy is

Correct Answer
verified
D

Correct Answer
verified

Your strange friend flies past you in a relativistic spacecraft holding a meterstick and a clock. The meterstick appears too _ to you, and the clock appears _ to you.

Correct Answer
verified
A

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

4 kilotons of TNT. This is equivalent to 9.0 × 10²⁶ MeV. The mass that was converted into energy in this explosion was

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

The total yearly world consumption of energy is approximately 4.0 × 10²⁰ J. How much mass would have to be completely converted into energy to provide this amount of energy?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

A proton and an electron are accelerated until their total energy is twice their rest masses. If the rest mass of the proton is M_pc² = 931 MeV and that of the electron is M_ec² = 0.51 MeV, the ratio of the velocity of the electron to that of the proton is

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified