Question 1

System  has a velocity u = +0.45c relative to system S,as shown in the figure.The clocks of S and  are synchronized at t =  = 0 when the origins O and  coincide.An event is observed in both systems.The event takes place at x = 600 m and at time t = 1.9 μs,as measured by an observer in S.What is the  -coordinate of the event,measured by an observer in  ?

Accepted Answer

A)  380 m 
B)  340 m 
C)  360 m 
D)  350 m 
E)  310 m

Question 2

An electron is accelerated from rest through a potential difference of 50.0 kV.What is the TOTAL energy of the electron? (c = 3.00 × 108 m/s,e = 1.60 × 10-19 C,

Accepted Answer

A)  8.00 × 10-15 J 
B)  16.2 × 10-15 J 
C)  8.20 × 10-14 J 
D)  9.00 × 10-14 J 
E)  16.2 × 10-14 J

Question 3

An astronaut in an inertial reference frame measures a time interval Δt between her heartbeats.What will observers in all other inertial reference frames measure for the time interval between her heartbeats?

Accepted Answer

A)  Δt 
B)  more thanΔt 
C)  less than Δt 
D)  The answer depends on whether they are moving toward her or away from her.

Question 4

How many joules of energy are required to accelerate a 1.0-kg mass from rest to a speed of 86.6% the speed of light? (c = 3.00 × 108 m/s)

Accepted Answer

A)  1.8 × 1017 J 
B)  9.0 × 1016 J 
C)  2.7 × 1012 J 
D)  4.5 × 109 J 
E)  3.0 × 103 J

Question 5

A particle is moving at 0.75c relative to a lab on Earth.By what percentage is the Newtonian expression for its momentum in error? (The percentage error is the difference between the erroneous and correct values,divided by the correct one).

Accepted Answer

A)  34% 
B)  28% 
C)  38% 
D)  43%

Question 6

A proton in a certain particle accelerator has a kinetic energy that is equal to its rest energy.What is the TOTAL energy of the proton as measured by a physicist working with the accelerator? (c = 3.00 × 108 m/s,mproton = 1.67 × 10-27 kg)

Accepted Answer

A)  5.69 × 10-11 J 
B)  1.50 × 10-10 J 
C)  2.07 × 10-10 J 
D)  3.01 × 10-10 J 
E)  8.77 × 10-10 J

Question 7

Two spaceships are approaching one another,each at a speed of 0.28c relative to a stationary observer on Earth.What speed does an observer on one spaceship record for the other approaching spaceship?

Accepted Answer

The answer of Two spaceships are approaching one another,each at...

Question 8

Two space stations are at rest relative to each other and are 6.0 × 107 m apart,as measured by observers on the stations.A spaceship traveling from one station to the other at 0.90c relative to the stations passes both of them,one after the other.As measured by an observer in the spaceship,how long does it take to travel from one station to the other?

Accepted Answer

A)  97 ms 
B)  220 ms 
C)  510 ms 
D)  58 ms 
E)  39 ms

Question 9

A navigational beacon in deep space broadcasts at a radio frequency of 50 MHz.A spaceship approaches the beacon with a relative velocity of 0.40c.What is the frequency of the beacon radio signal that is detected on the ship?

Accepted Answer

A)  55 MHz 
B)  60 MHz 
C)  66 MHz 
D)  71 MHz 
E)  76 MHz

Question 10

An electron has a speed of 0.643c.Through what potential difference would the electron need to be accelerated (starting from rest)in order to reach this speed? (c = 3.00 × 108 m/s,  ,mel = 9.11 × 10-31 kg)

Accepted Answer

A)  160 kV 
B)  130 kV 
C)  180 kV 
D)  200 kV

Question 11

You are a passenger on a spaceship.As the speed of the spaceship increases,you would observe that

Accepted Answer

A)  the length of your spaceship is getting shorter. 
B)  the length of your spaceship is getting longer. 
C)  the length of your spaceship is not changing.

Question 12

A rocket is moving at 1/4 the speed of light relative to Earth.At the center of this rocket,a light suddenly flashes.To an observer at rest on Earth

Accepted Answer

A)  the light will reach the front of the rocket at the same instant that it reaches the back of the rocket. 
B)  the light will reach the front of the rocket before it reaches the back of the rocket. 
C)  the light will reach the front of the rocket after it reaches the back of the rocket.

Question 13

A navigational beacon in deep space broadcasts at a radio frequency of 50 MHz.A spaceship approaches the beacon with a relative velocity of 0.40c.The spaceship passes the beacon and departs from it with a DIFFERENT relative velocity.The beacon signal is now detected at a frequency of 40 MHz.What is the new velocity of the spaceship relative to the beacon?

Accepted Answer

A)  0.20c 
B)  0.22c 
C)  0.24c 
D)  0.26c 
E)  0.28c

Question 14

A spaceship approaches the earth with a speed 0.50c.A passenger in the spaceship measures his heartbeat as 70 beats per minute.What is his heartbeat rate according to an observer that is at rest relative to the earth?

Accepted Answer

A)  69 beats per minute 
B)  73 beats per minute 
C)  65 beats per minute 
D)  61 beats per minute 
E)  80 beats per minute

Question 15

As measured in Earth's rest frame,a spaceship traveling at  takes  to travel between planets.How long does the trip take as measured by someone on the spaceship?

Accepted Answer

A)  2.98 y 
B)  7.28 y 
C)  42.1 y 
D)  30.7 y

Question 16

A spacecraft is measured by an observer on the ground to have a length of 53 m as it flies toward the earth with a speed 1.7 × 10⁸ m/s.The spacecraft then lands and its length is again measured by the observer on the ground,this time while the spacecraft is at rest on the launchpad.What result does he now get for the length?

Accepted Answer

The answer of A spacecraft is measured by an observer...

Question 17

Astronaut Mark Uri is space-traveling from planet X to planet Y at a speed of  relative to the planets,which are at rest relative to each other.When he is precisely halfway between the planets,a distance of 1.0 light-hour from each one as measured in the planet frame,nuclear devices are detonated on both planets.The explosions are simultaneous in Mark's frame.What is the difference in the time of arrival of the flashes from the explosions as observed by Mark?

Accepted Answer

A)  0 min 
B)  180 min 
C)  90 min 
D)  360 min 
E)  113 min

Question 18

During a nuclear reaction,1.7 × 10-4 J of energy is released.What is the resulting change in mass of the particles involved? (c = 3.00 × 108 m/s)

Accepted Answer

A)  5.1 × 10-4 kg 
B)  4.3 × 10-11 kg 
C)  1.5 × 10-13 kg 
D)  4.8 × 10-18 kg 
E)  1.9 × 10-21 kg

Question 19

Someone in Earth's rest frame says that a spaceship's trip between two planets took 10.0 y,while an astronaut on the space ship says that the trip took  Find the speed of the spaceship in terms of the speed of light.

Accepted Answer

A)  0.779c 
B)  0.687c 
C)  0.975c 
D)  0.384c

Question 20

Assume that a certain city consumes electrical energy at an average rate of 2.0 × 109 W.What would be the mass change in producing enough energy to keep this city running for 21 weeks?

Accepted Answer

A)  0.28 kg 
B)  0.32 kg 
C)  0.40 kg 
D)  0.48 kg

Exam 37: Relativity

An electron is accelerated from rest through a potential difference of 50.0 kV.What is the TOTAL energy of the electron? (c = 3.00 × 10⁸ m/s,e = 1.60 × 10^-19 C,

An astronaut in an inertial reference frame measures a time interval Δt between her heartbeats.What will observers in all other inertial reference frames measure for the time interval between her heartbeats?

How many joules of energy are required to accelerate a 1.0-kg mass from rest to a speed of 86.6% the speed of light? (c = 3.00 × 10⁸ m/s)

A particle is moving at 0.75c relative to a lab on Earth.By what percentage is the Newtonian expression for its momentum in error? (The percentage error is the difference between the erroneous and correct values,divided by the correct one) .

A proton in a certain particle accelerator has a kinetic energy that is equal to its rest energy.What is the TOTAL energy of the proton as measured by a physicist working with the accelerator? (c = 3.00 × 10⁸ m/s,m_proton = 1.67 × 10^-27 kg)

Two spaceships are approaching one another,each at a speed of 0.28c relative to a stationary observer on Earth.What speed does an observer on one spaceship record for the other approaching spaceship?

A navigational beacon in deep space broadcasts at a radio frequency of 50 MHz.A spaceship approaches the beacon with a relative velocity of 0.40c.What is the frequency of the beacon radio signal that is detected on the ship?

An electron has a speed of 0.643c.Through what potential difference would the electron need to be accelerated (starting from rest) in order to reach this speed? (c = 3.00 × 10⁸ m/s, ,m_el = 9.11 × 10^-31 kg)

You are a passenger on a spaceship.As the speed of the spaceship increases,you would observe that

A rocket is moving at 1/4 the speed of light relative to Earth.At the center of this rocket,a light suddenly flashes.To an observer at rest on Earth

A spaceship approaches the earth with a speed 0.50c.A passenger in the spaceship measures his heartbeat as 70 beats per minute.What is his heartbeat rate according to an observer that is at rest relative to the earth?

As measured in Earth's rest frame,a spaceship traveling at takes to travel between planets.How long does the trip take as measured by someone on the spaceship?

During a nuclear reaction,1.7 × 10^-4 J of energy is released.What is the resulting change in mass of the particles involved? (c = 3.00 × 10⁸ m/s)

Someone in Earth's rest frame says that a spaceship's trip between two planets took 10.0 y,while an astronaut on the space ship says that the trip took Find the speed of the spaceship in terms of the speed of light.

Assume that a certain city consumes electrical energy at an average rate of 2.0 × 10⁹ W.What would be the mass change in producing enough energy to keep this city running for 21 weeks?

Exam 37: Relativity

An electron is accelerated from rest through a potential difference of 50.0 kV.What is the TOTAL energy of the electron? (c = 3.00 × 108 m/s,e = 1.60 × 10-19 C,

An astronaut in an inertial reference frame measures a time interval Δt between her heartbeats.What will observers in all other inertial reference frames measure for the time interval between her heartbeats?

How many joules of energy are required to accelerate a 1.0-kg mass from rest to a speed of 86.6% the speed of light? (c = 3.00 × 108 m/s)

A particle is moving at 0.75c relative to a lab on Earth.By what percentage is the Newtonian expression for its momentum in error? (The percentage error is the difference between the erroneous and correct values,divided by the correct one) .

A proton in a certain particle accelerator has a kinetic energy that is equal to its rest energy.What is the TOTAL energy of the proton as measured by a physicist working with the accelerator? (c = 3.00 × 108 m/s,mproton = 1.67 × 10-27 kg)

Two spaceships are approaching one another,each at a speed of 0.28c relative to a stationary observer on Earth.What speed does an observer on one spaceship record for the other approaching spaceship?

A navigational beacon in deep space broadcasts at a radio frequency of 50 MHz.A spaceship approaches the beacon with a relative velocity of 0.40c.What is the frequency of the beacon radio signal that is detected on the ship?

An electron has a speed of 0.643c.Through what potential difference would the electron need to be accelerated (starting from rest) in order to reach this speed? (c = 3.00 × 108 m/s, ,mel = 9.11 × 10-31 kg)

You are a passenger on a spaceship.As the speed of the spaceship increases,you would observe that

A rocket is moving at 1/4 the speed of light relative to Earth.At the center of this rocket,a light suddenly flashes.To an observer at rest on Earth

A spaceship approaches the earth with a speed 0.50c.A passenger in the spaceship measures his heartbeat as 70 beats per minute.What is his heartbeat rate according to an observer that is at rest relative to the earth?

As measured in Earth's rest frame,a spaceship traveling at takes to travel between planets.How long does the trip take as measured by someone on the spaceship?

During a nuclear reaction,1.7 × 10-4 J of energy is released.What is the resulting change in mass of the particles involved? (c = 3.00 × 108 m/s)

Someone in Earth's rest frame says that a spaceship's trip between two planets took 10.0 y,while an astronaut on the space ship says that the trip took Find the speed of the spaceship in terms of the speed of light.

Assume that a certain city consumes electrical energy at an average rate of 2.0 × 109 W.What would be the mass change in producing enough energy to keep this city running for 21 weeks?

An electron is accelerated from rest through a potential difference of 50.0 kV.What is the TOTAL energy of the electron? (c = 3.00 × 10⁸ m/s,e = 1.60 × 10^-19 C,

How many joules of energy are required to accelerate a 1.0-kg mass from rest to a speed of 86.6% the speed of light? (c = 3.00 × 10⁸ m/s)

A proton in a certain particle accelerator has a kinetic energy that is equal to its rest energy.What is the TOTAL energy of the proton as measured by a physicist working with the accelerator? (c = 3.00 × 10⁸ m/s,m_proton = 1.67 × 10^-27 kg)

An electron has a speed of 0.643c.Through what potential difference would the electron need to be accelerated (starting from rest) in order to reach this speed? (c = 3.00 × 10⁸ m/s, ,m_el = 9.11 × 10^-31 kg)

During a nuclear reaction,1.7 × 10^-4 J of energy is released.What is the resulting change in mass of the particles involved? (c = 3.00 × 10⁸ m/s)

Assume that a certain city consumes electrical energy at an average rate of 2.0 × 10⁹ W.What would be the mass change in producing enough energy to keep this city running for 21 weeks?