Question 1

The experiment that dispelled the idea that light travels in the ether is called the:

Accepted Answer

A)  Michelson-Morley experiment. 
B)  Hafele and Keating experiment. 
C)  Fitzgerald-Kennedy experiment. 
D)  twin paradox. 
A)  Michelson-Morley experiment. 
B)  Hafele and Keating experiment. 
C)  Fitzgerald-Kennedy experiment. 
D)  twin paradox.

Question 2

Including relativistic effects,doubling the speed of a object:

Accepted Answer

A)  doubles its momentum. 
B)  more than doubles its momentum. 
C)  less than doubles its momentum. 
D)  has no effect on its momentum. 
A)  doubles its momentum. 
B)  more than doubles its momentum. 
C)  less than doubles its momentum. 
D)  has no effect on its momentum.

Question 3

A proton with mass 1.67 × 10−27 kg moves with a speed of 0.760 c in an accelerator.What is its relativistic momentum? (c = 3.00 × 108 m/s)

Accepted Answer

A)  3.65E-19 kg⋅m/s 
B)  7.90E-20 kg⋅m/s 
C)  5.61E-19 kg⋅m/s 
D)  2.37E-19 kg⋅m/s 
E)  ​4.80E-19 kg·m/s 
A)  3.65E-19 kg⋅m/s 
B)  7.90E-20 kg⋅m/s 
C)  5.61E-19 kg⋅m/s 
D)  2.37E-19 kg⋅m/s 
E)  ​4.80E-19 kg·m/s

Question 4

Relativity dealing with gravitation is known as:

Accepted Answer

A)  inertial relativity. 
B)  gravitational relativity. 
C)  Galilean relativity. 
D)  general relativity. 
A)  inertial relativity. 
B)  gravitational relativity. 
C)  Galilean relativity. 
D)  general relativity.

Question 5

A satellite is powered by a small nuclear generator that puts out 10 W.How much matter is converted into energy over the 20 year life span of the generator?

Accepted Answer

A)  70 µg 
B)  70 g 
C)  7 g 
D)  7 kg 
E)  ​4 mg 
A)  70 µg 
B)  70 g 
C)  7 g 
D)  7 kg 
E)  ​4 mg

Question 6

When a one-megaton nuclear bomb is exploded,approximately 4.0 × 1015 J of energy is released.How much mass would this represent in a mass-to-energy conversion? (c = 3.00 × 108 m/s)

Accepted Answer

A)  1.333 × 106 kg 
B)  0.044 kg 
C)  0.444 kg 
D)  3.600 kg 
E)  ​4.0 × 103 kg 
A)  1.333 × 106 kg 
B)  0.044 kg 
C)  0.444 kg 
D)  3.600 kg 
E)  ​4.0 × 103 kg

Question 7

A spaceship,which has length 35 m and width 16 m when at rest,is moving in a direction along its length at a speed where its length contraction results in a 28-m length measured by a stationary observer.What would the measured width be in this case?

Accepted Answer

A)  between 18 and 20 m 
B)  16 m 
C)  13 m 
D)  less than 13 m 
E)  ​20 m 
A)  between 18 and 20 m 
B)  16 m 
C)  13 m 
D)  less than 13 m 
E)  ​20 m

Question 8

The period of an oscillating weight on a spring in an inertial frame of reference is 2.5 s.What would be its speed if it were to move by an observer who measures its period as 3.4 s? (c = 3.00 × 108 m/s)

Accepted Answer

A)  1.5 × l08 m/s 
B)  2.0 × 108 m/s 
C)  2.8 × l08 m/s 
D)  6.8 × 107 m/s 
E)  ​1.3 × 108 m/s 
A)  1.5 × l08 m/s 
B)  2.0 × 108 m/s 
C)  2.8 × l08 m/s 
D)  6.8 × 107 m/s 
E)  ​1.3 × 108 m/s

Question 9

A space probe has an 15.6-m length when measured at rest.What length does an observer at rest measure when the probe is going by at a speed of 0.740 c?

Accepted Answer

A)  23.2 m 
B)  10.5 m 
C)  8.0 m 
D)  11.5 m 
E)  ​21.1 m 
A)  23.2 m 
B)  10.5 m 
C)  8.0 m 
D)  11.5 m 
E)  ​21.1 m

Question 10

From a stationary position,I observe a moving boxcar,which has a mirror along the front wall,but it is open at the back of the boxcar.I send a flash of light from my flashlight and time the flash of light as it goes to the front of the boxcar and returns to the back of the boxcar.A passenger in the boxcar also times the round trip of the flash of light.Previously I had measured the time required for the round trip of a flash of light when the boxcar was stationary,and I call this the stationary time.Which two times are the same?

Accepted Answer

A)  the time recorded on my watch and the previous stationary time 
B)  the time recorded on the passenger's watch and the previous stationary time 
C)  the time recorded on my watch and the time recorded on the passenger's watch 
D)  None of the times are the same. 
A)  the time recorded on my watch and the previous stationary time 
B)  the time recorded on the passenger's watch and the previous stationary time 
C)  the time recorded on my watch and the time recorded on the passenger's watch 
D)  None of the times are the same.

Question 11

The significant result of the Michelson-Morley experiment was that it found:

Accepted Answer

A)  the ether moved with the sun. 
B)  the ether moved with the Earth. 
C)  the speed of the ether wind was greater than expected. 
D)  no effect. 
A)  the ether moved with the sun. 
B)  the ether moved with the Earth. 
C)  the speed of the ether wind was greater than expected. 
D)  no effect.

Question 12

Muons at speed 0.9995 c are sent round and round a circular storage ring of radius 550 m.If a muon at rest decays into other particles after an average T =2.2 × 10−6 s,how many trips around the storage ring do we expect the 0.9995 c muons to make before they decay?

Accepted Answer

A)  1 
B)  2 
C)  12 
D)  6 
E)  ​131 
A)  1 
B)  2 
C)  12 
D)  6 
E)  ​131

Question 13

If the total energy of an electron in an accelerator is three times its rest energy,what is its speed? (c = 3.00 × 108 m/s)

Accepted Answer

A)  2.00 × 108 m/s 
B)  1.30 × 108 m/s 
C)  1.41 × 108 m/s 
D)  2.98 × 108 m/s 
E)  ​2.83 × 108 m/s 
A)  2.00 × 108 m/s 
B)  1.30 × 108 m/s 
C)  1.41 × 108 m/s 
D)  2.98 × 108 m/s 
E)  ​2.83 × 108 m/s

Question 14

If a proton with mass 1.67 × 10−27 kg moves in an accelerator such that its total energy is three times its rest energy,what is its speed? (c = 3.00 × 108 m/s)

Accepted Answer

A)  2.83 × 108 m/s 
B)  2.45 × 108 m/s 
C)  2.00 × 108 m/s 
D)  1.00 × 108 m/s 
E)  ​1.54 × 108 m/s 
A)  2.83 × 108 m/s 
B)  2.45 × 108 m/s 
C)  2.00 × 108 m/s 
D)  1.00 × 108 m/s 
E)  ​1.54 × 108 m/s

Question 15

At what speed is the momentum of an object five times that found classically?

Accepted Answer

A)  0.894 c 
B)  0.960 c 
C)  0.980 c 
D)  0.800 c 
E)  ​0.999 c 
A)  0.894 c 
B)  0.960 c 
C)  0.980 c 
D)  0.800 c 
E)  ​0.999 c

Question 16

What is the relativistic kinetic energy of an electron moving at a speed of 2.30 × 108 m/s? (electron mass is 9.11 × 10−31 kg and c = 3.00 × 108 m/s)

Accepted Answer

A)  4.57E-14 J 
B)  1.28E-13 J 
C)  5.26E-14 J 
D)  3.38E-14 J 
E)  ​8.20E-14 J 
A)  4.57E-14 J 
B)  1.28E-13 J 
C)  5.26E-14 J 
D)  3.38E-14 J 
E)  ​8.20E-14 J

Question 17

At what speed must an object be moving in order that it has a kinetic energy 2.6 times its rest energy? (c = 3.00 × 108 m/s)

Accepted Answer

A)  2.77 × 108 m/s 
B)  2.17 × 108 m/s 
C)  2.88 × 108 m/s 
D)  1.15 × 108 m/s 
E)  ​2.55 × 108 m/s 
A)  2.77 × 108 m/s 
B)  2.17 × 108 m/s 
C)  2.88 × 108 m/s 
D)  1.15 × 108 m/s 
E)  ​2.55 × 108 m/s

Question 18

The observed relativistic length of a super rocket moving by the observer at 0.70 c will be what factor times that of the measured rocket length if it were at rest?

Accepted Answer

A)  0.55 
B)  0.71 
C)  0.51 
D)  1.4 
E)  ​1.8 
A)  0.55 
B)  0.71 
C)  0.51 
D)  1.4 
E)  ​1.8

Question 19

The Michelson-Morley experiment was designed to make use of ________ to find the motion of the Earth relative to the luminiferous ether.

Accepted Answer

A)  sound waves 
B)  interference fringes 
C)  electromagnetic wind 
D)  none of the above 
A)  sound waves 
B)  interference fringes 
C)  electromagnetic wind 
D)  none of the above

Question 20

If the nonzero momentum of a particle with mass is doubled,what happens to its total energy?

Accepted Answer

A)  It also doubles. 
B)  It increases,more than doubling. 
C)  It stays the same since total energy is a constant for a given particle. 
D)  It increases,but less than doubling. 
A)  It also doubles. 
B)  It increases,more than doubling. 
C)  It stays the same since total energy is a constant for a given particle. 
D)  It increases,but less than doubling.

Exam 26: Relativity

The experiment that dispelled the idea that light travels in the ether is called the:

Including relativistic effects,doubling the speed of a object:

A proton with mass 1.67 × 10−27 kg moves with a speed of 0.760 c in an accelerator.What is its relativistic momentum? (c = 3.00 × 108 m/s)

Relativity dealing with gravitation is known as:

A satellite is powered by a small nuclear generator that puts out 10 W.How much matter is converted into energy over the 20 year life span of the generator?

When a one-megaton nuclear bomb is exploded,approximately 4.0 × 1015 J of energy is released.How much mass would this represent in a mass-to-energy conversion? (c = 3.00 × 108 m/s)

A spaceship,which has length 35 m and width 16 m when at rest,is moving in a direction along its length at a speed where its length contraction results in a 28-m length measured by a stationary observer.What would the measured width be in this case?

The period of an oscillating weight on a spring in an inertial frame of reference is 2.5 s.What would be its speed if it were to move by an observer who measures its period as 3.4 s? (c = 3.00 × 108 m/s)

A space probe has an 15.6-m length when measured at rest.What length does an observer at rest measure when the probe is going by at a speed of 0.740 c?

The significant result of the Michelson-Morley experiment was that it found:

Muons at speed 0.9995 c are sent round and round a circular storage ring of radius 550 m.If a muon at rest decays into other particles after an average T =2.2 × 10−6 s,how many trips around the storage ring do we expect the 0.9995 c muons to make before they decay?

If the total energy of an electron in an accelerator is three times its rest energy,what is its speed? (c = 3.00 × 108 m/s)

If a proton with mass 1.67 × 10−27 kg moves in an accelerator such that its total energy is three times its rest energy,what is its speed? (c = 3.00 × 108 m/s)

At what speed is the momentum of an object five times that found classically?

What is the relativistic kinetic energy of an electron moving at a speed of 2.30 × 108 m/s? (electron mass is 9.11 × 10−31 kg and c = 3.00 × 108 m/s)

At what speed must an object be moving in order that it has a kinetic energy 2.6 times its rest energy? (c = 3.00 × 108 m/s)

The observed relativistic length of a super rocket moving by the observer at 0.70 c will be what factor times that of the measured rocket length if it were at rest?

The Michelson-Morley experiment was designed to make use of ________ to find the motion of the Earth relative to the luminiferous ether.

If the nonzero momentum of a particle with mass is doubled,what happens to its total energy?

Introduction

Introduction: Part A

Motion in One Dimension

Motion in One Dimension: Part A

Vectors and Two-Dimensional Motion

Vectors and Two-Dimensional Motion: Part A

The Laws of Motion

The Laws of Motion: Part A

Energy

Energy: Part A

Momentum and Collisions

Momentum and Collisions: Part A

Rotational Motion and the Law of Gravity

Rotational Motion and the Law of Gravity: Part A

Rotational Equilibrium and Rotational Dynamics

Rotational Equilibrium and Rotational Dynamics: Part A

Solids and Fluids

Solids and Fluids: Part A

Thermal Physics

Thermal Physics: Part A

Energy in Thermal Processes Heat and Internal Energy

Energy in Thermal Processes Heat and Internal Energy: Part A

The Laws of Thermodynamics Work in Thermodynamic Processes

The Laws of Thermodynamics Work in Thermodynamic Processes: Part A

Vibrations and Waves

Vibrations and Waves: Part A

Sound

Sound: Part A

Electric Forces and Electric Fields

Electric Forces and Electric Fields: Part A

Electrical Energy and Capacitance

Electrical Energy and Capacitance: Part A

Current and Resistance Electric Current

Current and Resistance Electric Current: Part A

Direct-Current Circuits Sources of EMF

Direct-Current Circuits Sources of EMF: Part A

Magnetism Magnets

Magnetism Magnets: Part A

Induced Voltages and Inductance

Induced Voltages and Inductance: Part A

Alternating-Current Circuits and Electromagnetic Waves

Alternating-Current Circuits and Electromagnetic Waves: Part A

Reflection and Refraction of Light

Reflection and Refraction of Light: Part A

Mirrors and Lenses

Mirrors and Lenses: Part A

Wave Optics

Wave Optics: Part A

Optical Instruments

Optical Instruments: Part A

Relativity: Part A

Quantum Physics Blackbody Radiation and Plancks Hypothesis

Quantum Physics Blackbody Radiation and Plancks Hypothesis: Part A

Atomic Physics

Atomic Physics: Part A

Nuclear Physics

Nuclear Physics: Part A

Nuclear Energy and Elementary Particles

Nuclear Energy and Elementary Particles: Part A

Particle Collisions, Mediating Photons, and Quark Structures: Exploring the Fundamentals of Physics

A proton with mass 1.67 × 10−²⁷ kg moves with a speed of 0.760 c in an accelerator.What is its relativistic momentum? (c = 3.00 × 10⁸ m/s)

When a one-megaton nuclear bomb is exploded,approximately 4.0 × 10¹⁵ J of energy is released.How much mass would this represent in a mass-to-energy conversion? (c = 3.00 × 10⁸ m/s)

The period of an oscillating weight on a spring in an inertial frame of reference is 2.5 s.What would be its speed if it were to move by an observer who measures its period as 3.4 s? (c = 3.00 × 10⁸ m/s)

Muons at speed 0.9995 c are sent round and round a circular storage ring of radius 550 m.If a muon at rest decays into other particles after an average T =2.2 × 10−⁶ s,how many trips around the storage ring do we expect the 0.9995 c muons to make before they decay?

If the total energy of an electron in an accelerator is three times its rest energy,what is its speed? (c = 3.00 × 10⁸ m/s)

If a proton with mass 1.67 × 10−²⁷ kg moves in an accelerator such that its total energy is three times its rest energy,what is its speed? (c = 3.00 × 10⁸ m/s)

What is the relativistic kinetic energy of an electron moving at a speed of 2.30 × 10⁸ m/s? (electron mass is 9.11 × 10−³¹ kg and c = 3.00 × 10⁸ m/s)

At what speed must an object be moving in order that it has a kinetic energy 2.6 times its rest energy? (c = 3.00 × 10⁸ m/s)