Question 1

A proton with mass 1.67 × 10−27 kg moves with a speed of 0.560 c in an accelerator.What is its kinetic energy? (c = 3.00 × 108 m/s)

Accepted Answer

A)  1.50E-10 J 
B)  1.81E-10 J 
C)  3.11E-11 J 
D)  1.03E-10 J 
E)  ​4.71E-11 J 
A)  1.50E-10 J 
B)  1.81E-10 J 
C)  3.11E-11 J 
D)  1.03E-10 J 
E)  ​4.71E-11 J C

Question 2

A boxcar without a front or a back is moving toward the right.Two flashes of light move through the boxcar,one moving from back to front toward the right,the other moving from front to back toward the left.A passenger in the boxcar records how long it takes each flash of light to pass from one end of the boxcar to the other end.According to the passenger,which took longer?

Accepted Answer

A)  the flash going from back to front 
B)  the flash going from front to back 
C)  They both took the same time. 
D)  It depends on whether the passenger is sitting at the front or the back of the boxcar. 
A)  the flash going from back to front 
B)  the flash going from front to back 
C)  They both took the same time. 
D)  It depends on whether the passenger is sitting at the front or the back of the boxcar. C

Question 3

As the speed of an object increases,its relativistic momentum:

Accepted Answer

A)  stays the same as its classical momentum. 
B)  increases more than its classical momentum. 
C)  increases less than it classical momentum. 
D)  does not change since momentum is a conserved quantity. 
A)  stays the same as its classical momentum. 
B)  increases more than its classical momentum. 
C)  increases less than it classical momentum. 
D)  does not change since momentum is a conserved quantity. C

Question 4

A lump of uranium has a mass of 2.0 kg,and begins at rest.Half of the lump's mass is going to be totally converted into kinetic energy of the other half.After this is done,how fast is the remaining half going?

Accepted Answer

A)  0.60 c 
B)  0.80 c 
C)  0.87 c 
D)  1.0 c 
A)  0.60 c 
B)  0.80 c 
C)  0.87 c 
D)  1.0 c

Question 5

A spaceship is moving away from an observer at relativistic speed.Its length at rest is 100 m,but the observer measures its length as 60 m.A time interval of 84 s on the spaceship would be measured by the observer to be which of the following?

Accepted Answer

A)  50.4 s 
B)  30.2 s 
C)  134 s 
D)  140 s 
E)  ​84 s 
A)  50.4 s 
B)  30.2 s 
C)  134 s 
D)  140 s 
E)  ​84 s

Question 6

A tuning fork has a frequency of 300 Hz and hence a period of 3.33 × 10−3 s.If the tuning fork is in an inertial frame of reference moving by the observer at speed of 0.620 c,what is the frequency of the fork as measured by the observer? (Assume that measurements are strictly by optical means and that the speed of sound waves in air is not pertinent here).

Accepted Answer

A)  235 Hz 
B)  382 Hz 
C)  185 Hz 
D)  185 Hz. 
E)  ​487 Hz 
A)  235 Hz 
B)  382 Hz 
C)  185 Hz 
D)  185 Hz. 
E)  ​487 Hz

Question 7

What is the total energy of a proton moving at a speed of 2.4 × 108 m/s? (proton mass is 1.67 × 10−27 kg and c = 3.00 × 108 m/s)

Accepted Answer

A)  1.91E-10 J 
B)  1.77E-10 J 
C)  2.51E-10 J 
D)  2.44E-10 J 
E)  ​9.02E-11 J 
A)  1.91E-10 J 
B)  1.77E-10 J 
C)  2.51E-10 J 
D)  2.44E-10 J 
E)  ​9.02E-11 J

Question 8

In a test of equipment the following procedure is carried out.Spacecraft №1 is traveling at 0.75 c and fires a laser pulse in the forward direction at Spacecraft №2,which is testing its device that measures the speed of laser pulses as they pass by the spacecraft.Spacecraft №2 is traveling at 0.95 c in a direction away from Spacecraft №1.The device is working properly,and the speed of the pulse as it passes is successfully measured.What is the speed of the laser pulse measured in this case?

Accepted Answer

A)  0.80 c 
B)  0.70 c 
C)  c 
D)  This is a question that cannot be answered without knowing in which reference frames the speeds given in the problem.If you agree,then this is the answer that you should choose. 
A)  0.80 c 
B)  0.70 c 
C)  c 
D)  This is a question that cannot be answered without knowing in which reference frames the speeds given in the problem.If you agree,then this is the answer that you should choose.

Question 9

The total energy of a particle:

Accepted Answer

A)  is not related to its relativistic momentum. 
B)  increases with increasing relativistic momentum. 
C)  decreases with increasing relativistic momentum. 
D)  is a constant. 
A)  is not related to its relativistic momentum. 
B)  increases with increasing relativistic momentum. 
C)  decreases with increasing relativistic momentum. 
D)  is a constant.

Question 10

Which form of relativity applies for observers who are accelerating?

Accepted Answer

A)  Special relativity applies. 
B)  General relativity applies. 
C)  Both special relativity and general relativity apply. 
D)  Neither applies since the observer must be in an inertial frame to use either one. 
A)  Special relativity applies. 
B)  General relativity applies. 
C)  Both special relativity and general relativity apply. 
D)  Neither applies since the observer must be in an inertial frame to use either one.

Question 11

If the mass of a proton is 1.67 × 10−27 kg,what is the rest energy of the proton? (c = 3.00 × 108 m/s and 1 eV = 1.6 × 10−19 J)

Accepted Answer

A)  1.2 × 108 eV 
B)  3.7 × 108 eV 
C)  4.1 × 108 eV 
D)  9.4 × 108 eV 
A)  1.2 × 108 eV 
B)  3.7 × 108 eV 
C)  4.1 × 108 eV 
D)  9.4 × 108 eV

Question 12

According to a postulate of Einstein,which of the following describes the nature of the laws of physics as one observes processes taking place in various inertial frames of reference?

Accepted Answer

A)  Laws are same only in inertial frames with zero velocity. 
B)  Laws are same only in inertial frames moving at low velocities. 
C)  Laws are same only in inertial frames moving at near speed of light. 
D)  Laws are same in all inertial frames. 
A)  Laws are same only in inertial frames with zero velocity. 
B)  Laws are same only in inertial frames moving at low velocities. 
C)  Laws are same only in inertial frames moving at near speed of light. 
D)  Laws are same in all inertial frames.

Question 13

According to the special theory of relativity,which of the following happens to the size of the time interval between two events occurring in an inertial frame of reference as the frame's velocity with respect to the observer increases?

Accepted Answer

A)  interval increases 
B)  interval decreases 
C)  interval remains constant 
D)  interval vanishes to zero when velocity equals half speed of light 
A)  interval increases 
B)  interval decreases 
C)  interval remains constant 
D)  interval vanishes to zero when velocity equals half speed of light

Question 14

I am stationary in a reference system but if my reference system is not an inertial reference system,then,relative to me,a system that is an inertial reference system must:

Accepted Answer

A)  remain at rest. 
B)  move with constant velocity. 
C)  be accelerating. 
D)  be none of the above. 
A)  remain at rest. 
B)  move with constant velocity. 
C)  be accelerating. 
D)  be none of the above.

Question 15

At what speed would a clock have to be moving in order to run at a rate that is one-fourth the rate of a clock at rest?

Accepted Answer

A)  0.87 c 
B)  0.75 c 
C)  0.97 c 
D)  0.50 c 
E)  ​0.26 c 
A)  0.87 c 
B)  0.75 c 
C)  0.97 c 
D)  0.50 c 
E)  ​0.26 c

Question 16

How fast would a rocket have to move past a ground observer if the latter were to observe a 9.4% length shrinkage in the rocket length? (c = 3.00 × 108 m/s)

Accepted Answer

A)  2.98 × 108 m/s 
B)  2.72 × 108 m/s 
C)  1.27 × 108 m/s 
D)  0.420 × 108 m/s 
E)  ​0.920 × 108 m/s 
A)  2.98 × 108 m/s 
B)  2.72 × 108 m/s 
C)  1.27 × 108 m/s 
D)  0.420 × 108 m/s 
E)  ​0.920 × 108 m/s

Question 17

An astronaut at rest has a heart rate of 68 beats/min.What will her heart rate be as measured by an earth observer when the astronaut's spaceship goes by the earth at a speed of 0.76 c?

Accepted Answer

A)  105 beats/min 
B)  52 beats/min 
C)  33 beats/min 
D)  139 beats/min 
E)  ​44 beats/min 
A)  105 beats/min 
B)  52 beats/min 
C)  33 beats/min 
D)  139 beats/min 
E)  ​44 beats/min

Question 18

According to the special theory of relativity,if a 30-year old astronaut sent on a space mission is accelerated to speeds close to that of light,and then returns to earth after 20 years as measured on earth,what would be his biological age upon returning?

Accepted Answer

A)  less than 50 years 
B)  50 years 
C)  more than 50 years 
D)  exactly 100 years 
A)  less than 50 years 
B)  50 years 
C)  more than 50 years 
D)  exactly 100 years

Question 19

An unknown particle in an accelerator moving at a speed of 1.50 × 108 m/s has a measured total energy of 3.30 × 10−9 J.What is its mass? (c = 3.00 × 108 m/s)

Accepted Answer

A)  4.23E-26 kg 
B)  9.17E-27 kg 
C)  7.78E-26 kg 
D)  3.18E-26 kg 
E)  ​3.67E-26 kg 
A)  4.23E-26 kg 
B)  9.17E-27 kg 
C)  7.78E-26 kg 
D)  3.18E-26 kg 
E)  ​3.67E-26 kg

Question 20

The mass of a proton at rest is m. If the proton is moving so fast that its total energy is three times its rest energy,then what is the kinetic energy of the proton?

Accepted Answer

A)  mc2 
B)  2mc2 
C)  3mc2 
D)  4mc2 
A)  mc2 
B)  2mc2 
C)  3mc2 
D)  4mc2

Exam 26: Relativity

A proton with mass 1.67 × 10−27 kg moves with a speed of 0.560 c in an accelerator.What is its kinetic energy? (c = 3.00 × 108 m/s)

As the speed of an object increases,its relativistic momentum:

A lump of uranium has a mass of 2.0 kg,and begins at rest.Half of the lump's mass is going to be totally converted into kinetic energy of the other half.After this is done,how fast is the remaining half going?

A spaceship is moving away from an observer at relativistic speed.Its length at rest is 100 m,but the observer measures its length as 60 m.A time interval of 84 s on the spaceship would be measured by the observer to be which of the following?

What is the total energy of a proton moving at a speed of 2.4 × 108 m/s? (proton mass is 1.67 × 10−27 kg and c = 3.00 × 108 m/s)

The total energy of a particle:

Which form of relativity applies for observers who are accelerating?

If the mass of a proton is 1.67 × 10−27 kg,what is the rest energy of the proton? (c = 3.00 × 108 m/s and 1 eV = 1.6 × 10−19 J)

According to a postulate of Einstein,which of the following describes the nature of the laws of physics as one observes processes taking place in various inertial frames of reference?

According to the special theory of relativity,which of the following happens to the size of the time interval between two events occurring in an inertial frame of reference as the frame's velocity with respect to the observer increases?

I am stationary in a reference system but if my reference system is not an inertial reference system,then,relative to me,a system that is an inertial reference system must:

At what speed would a clock have to be moving in order to run at a rate that is one-fourth the rate of a clock at rest?

How fast would a rocket have to move past a ground observer if the latter were to observe a 9.4% length shrinkage in the rocket length? (c = 3.00 × 108 m/s)

An astronaut at rest has a heart rate of 68 beats/min.What will her heart rate be as measured by an earth observer when the astronaut's spaceship goes by the earth at a speed of 0.76 c?

According to the special theory of relativity,if a 30-year old astronaut sent on a space mission is accelerated to speeds close to that of light,and then returns to earth after 20 years as measured on earth,what would be his biological age upon returning?

An unknown particle in an accelerator moving at a speed of 1.50 × 108 m/s has a measured total energy of 3.30 × 10−9 J.What is its mass? (c = 3.00 × 108 m/s)

The mass of a proton at rest is m. If the proton is moving so fast that its total energy is three times its rest energy,then what is the kinetic energy of the proton?

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

Filters

A proton with mass 1.67 × 10−²⁷ kg moves with a speed of 0.560 c in an accelerator.What is its kinetic energy? (c = 3.00 × 10⁸ m/s)

What is the total energy of a proton moving at a speed of 2.4 × 10⁸ m/s? (proton mass is 1.67 × 10−²⁷ kg and c = 3.00 × 10⁸ m/s)

If the mass of a proton is 1.67 × 10−²⁷ kg,what is the rest energy of the proton? (c = 3.00 × 10⁸ m/s and 1 eV = 1.6 × 10−¹⁹ J)

How fast would a rocket have to move past a ground observer if the latter were to observe a 9.4% length shrinkage in the rocket length? (c = 3.00 × 10⁸ m/s)

An unknown particle in an accelerator moving at a speed of 1.50 × 10⁸ m/s has a measured total energy of 3.30 × 10−⁹ J.What is its mass? (c = 3.00 × 10⁸ m/s)

The mass of a proton at rest is m_. If the proton is moving so fast that its total energy is three times its rest energy,then what is the kinetic energy of the proton?