Question 1

Shawn is traveling away from you at a speed of 120 km/hr.He throws a baseball that,according to him,is going at 100 km/hr in your direction.What do you see the ball doing?

Accepted Answer

A) You see the ball traveling away from you at 120 km/hr. 
B) You see the ball traveling away from you at 100 km/hr. 
C) You see the ball traveling away from you at 220 km/hr. 
D) You see the ball traveling toward you at 20 km/hr. 
E) You see the ball traveling away from you at 20 km/hr. 
A) You see the ball traveling away from you at 120 km/hr. 
B) You see the ball traveling away from you at 100 km/hr. 
C) You see the ball traveling away from you at 220 km/hr. 
D) You see the ball traveling toward you at 20 km/hr. 
E) You see the ball traveling away from you at 20 km/hr.

Question 2

Ben is racing a light beam in a 100-meter dash.Ben bursts out of the starting blocks at 99 percent of the speed of light (0.99c).At the same instant,a flashlight beam is turned on from the starting blocks.
-How does the explosion of a nuclear bomb provide evidence of the theory of relativity?

Accepted Answer

A) The bomb causes things in its vicinity to move at very high speeds,allowing scientists to measure effects of time dilation. 
B) The mass of the bomb when it explodes is much greater than its normal mass. 
C) The bomb shortens the lifetimes of all people who happen to be near it when it detonates. 
D) The bomb produces energy in accord with E = mc²,which is part of the theory of relativity. 
A) The bomb causes things in its vicinity to move at very high speeds,allowing scientists to measure effects of time dilation. 
B) The mass of the bomb when it explodes is much greater than its normal mass. 
C) The bomb shortens the lifetimes of all people who happen to be near it when it detonates. 
D) The bomb produces energy in accord with E = mc²,which is part of the theory of relativity.

Question 3

You are in an airplane,traveling relative to the ground at 500 km/hr.You throw a baseball toward the front of the plane at a speed of 50 km/hr.How fast would someone on the ground say the baseball is moving?

Accepted Answer

A) 550 km/hr 
B) 50 km/hr 
C) 500 km/hr 
D) 450 km/hr. 
A) 550 km/hr 
B) 50 km/hr 
C) 500 km/hr 
D) 450 km/hr.

Question 4

You are racing away from Earth in a super spaceship in which you can continually increase your speed.Which of the following best explains how people on Earth will perceive your speed?

Accepted Answer

A) They will know you are going very fast but will have no way of knowing whether you ever exceed the speed of light. 
B) You will see any beam of light from Earth coming toward you at the speed of light,which means it will catch you.Thus,the people on Earth must conclude that you are going slower than the speed of light. 
C) An imaginary spaceship can go as fast as it wants,so the folks on Earth soon will see you going faster than the speed of light. 
D) You may soon be racing away from Earth faster than the speed of light,but,if so,people on Earth will no longer be able to see you. 
E) Without more information,it is impossible to know how fast you would see a light beam from Earth coming toward you.If it happens that you are going fast enough so that the light can't catch you,then people on Earth would find you to be going faster than light. 
A) They will know you are going very fast but will have no way of knowing whether you ever exceed the speed of light. 
B) You will see any beam of light from Earth coming toward you at the speed of light,which means it will catch you.Thus,the people on Earth must conclude that you are going slower than the speed of light. 
C) An imaginary spaceship can go as fast as it wants,so the folks on Earth soon will see you going faster than the speed of light. 
D) You may soon be racing away from Earth faster than the speed of light,but,if so,people on Earth will no longer be able to see you. 
E) Without more information,it is impossible to know how fast you would see a light beam from Earth coming toward you.If it happens that you are going fast enough so that the light can't catch you,then people on Earth would find you to be going faster than light.

Question 5

What is the primary reason why scientists accept the idea that the speed of light is the same for everyone?

Accepted Answer

A) because it makes sense when you think about it as Einstein did 
B) because it has been verified by many observations and experiments 
C) because no one has come up with a better idea about the speed of light 
D) because the theory is just so darn cool,it can't be wrong 
A) because it makes sense when you think about it as Einstein did 
B) because it has been verified by many observations and experiments 
C) because no one has come up with a better idea about the speed of light 
D) because the theory is just so darn cool,it can't be wrong

Question 6

Bob is in a spaceship going by you at 90% of the speed of light,but in an upright standing position.Bob measures his mass to be 50 kg,his height to be 2.0 meters,and his waist size to be 80 cm.What would you say about his measurements?

Accepted Answer

A) His mass is more than 50 kg,his height is still 2.0 meters,and his waist size is less than 80 cm. 
B) His mass is more than 50 kg,his height is less than 2.0 meters,and his waist size is less than 80 cm. 
C) His mass is less than 50 kg,his height is more 2.0 meters,and his waist size is less than 80 cm. 
D) You would measure the same mass and size as he does. 
A) His mass is more than 50 kg,his height is still 2.0 meters,and his waist size is less than 80 cm. 
B) His mass is more than 50 kg,his height is less than 2.0 meters,and his waist size is less than 80 cm. 
C) His mass is less than 50 kg,his height is more 2.0 meters,and his waist size is less than 80 cm. 
D) You would measure the same mass and size as he does.

Question 7

Different observers can disagree about the speed of a baseball,but they cannot disagree about the speed of a light beam.

Accepted Answer

A) True 
 B)False

Question 8

Use the appropriate relativity formula given in the text to answer the following: Isabella is moving by you at a speed of 0.8c.While 1 minute passes on your watch,how much time will you see pass on her watch?

Accepted Answer

A) 36 seconds 
B) 1 minute 
C) 48 seconds 
D) 100 seconds 
A) 36 seconds 
B) 1 minute 
C) 48 seconds 
D) 100 seconds

Question 9

How does the explosion of a nuclear bomb provide evidence for the theory of relativity?

Accepted Answer

A) The mass of the bomb when it explodes is much greater than its normal mass. 
B) bomb causes things in its vicinity to move at very high speeds,allowing scientists to measure effects of time dilation. 
C) The bomb shortens the lifetimes of all people who happen to be near it when it detonates. 
D) The bomb converts rest-mass energy into thermal energy in accord with E = mc²,which is part of the theory of relativity. 
A) The mass of the bomb when it explodes is much greater than its normal mass. 
B) bomb causes things in its vicinity to move at very high speeds,allowing scientists to measure effects of time dilation. 
C) The bomb shortens the lifetimes of all people who happen to be near it when it detonates. 
D) The bomb converts rest-mass energy into thermal energy in accord with E = mc²,which is part of the theory of relativity.

Question 10

Again consider two twin sisters,Gwen and Jackie,who are both 20 years old in the year 2020.This time,assume that Jackie makes the round-trip to Vega,which is 25 light-years away,at an average speed of 0.9999c.Which of the following correctly describes the situation when Jackie returns to Earth? (Ages in this problem refer to biological ages-that is,how much time has passed for each sister since she was born. )

Accepted Answer

A) It's the year 2070.Gwen (who stayed home)is 70 years old,but Jackie is only a little older than her age of 20 when she left. 
B) It's the year 2070 and both twin sisters are 70 years old. 
C) It's the year 2070.Gwen is 70 years old.Jackie is 19. 
D) According to Gwen,Jackie returns to Earth in the year 2070,but according to Jackie,she returns in the year 2021. 
A) It's the year 2070.Gwen (who stayed home)is 70 years old,but Jackie is only a little older than her age of 20 when she left. 
B) It's the year 2070 and both twin sisters are 70 years old. 
C) It's the year 2070.Gwen is 70 years old.Jackie is 19. 
D) According to Gwen,Jackie returns to Earth in the year 2070,but according to Jackie,she returns in the year 2021.

Question 11

Which of the following is not true of the special theory of relativity?

Accepted Answer

A) The special theory does not apply to situations that involve substantial acceleration or gravity;for that,you need the general theory of relativity. 
B) For low speeds,the theory predicts effects that are so small that they cannot be noticed without extremely precise,high-tech measurement. 
C) The theory is valid only at speeds close to the speed of light. 
D) The theory tells us that there is no such thing as absolute time or space,because measurements of time and space depend on your reference frame. 
A) The special theory does not apply to situations that involve substantial acceleration or gravity;for that,you need the general theory of relativity. 
B) For low speeds,the theory predicts effects that are so small that they cannot be noticed without extremely precise,high-tech measurement. 
C) The theory is valid only at speeds close to the speed of light. 
D) The theory tells us that there is no such thing as absolute time or space,because measurements of time and space depend on your reference frame.

Question 12

Which of the following is not a prediction made by the theory of relativity?

Accepted Answer

A) No material object sent outward from Earth can reach or exceed the speed of light. 
B) Observers in different reference frames may disagree about whether two events in two different places occur simultaneously. 
C) Observers in different reference frames may disagree about the time and distance between two events. 
D) Observers in different reference frames may disagree about the basic laws of nature. 
E) E = mc² 
A) No material object sent outward from Earth can reach or exceed the speed of light. 
B) Observers in different reference frames may disagree about whether two events in two different places occur simultaneously. 
C) Observers in different reference frames may disagree about the time and distance between two events. 
D) Observers in different reference frames may disagree about the basic laws of nature. 
E) E = mc²

Question 13

How would we view time (clocks)on the spaceship as it goes by?

Accepted Answer

A) Time is the same for everyone. 
B) Their clocks are going at the same rate as ours. 
C) Their clocks are going exactly half as fast as ours. 
D) Their clocks are going faster than ours. 
E) Their clocks are going slower than ours. 
A) Time is the same for everyone. 
B) Their clocks are going at the same rate as ours. 
C) Their clocks are going exactly half as fast as ours. 
D) Their clocks are going faster than ours. 
E) Their clocks are going slower than ours.

Question 14

You take a trip to a star located 1,000 light-years away and return.You travel at an average speed of 0.99c.
HINT: The time dilation formula is: 
$ t^{\prime}=\sqrt[t]{1-\left(\frac{v}{c}\right)^{2}} $
-About how many years will pass on Earth while you are gone?

Accepted Answer

A) 2.8 years 
B) 10 years 
C) 28 years 
D) 2,000 years 
E) 280 years 
A) 2.8 years 
B) 10 years 
C) 28 years 
D) 2,000 years 
E) 280 years

Question 15

Julia is traveling away from you at 0.95c when she shoots a probe forward from her spacecraft.According to her,the probe travels at 0.8c.How fast do you see the probe going?

Accepted Answer

This problem is simply velocity addition

Question 16

Which of the following correctly describes the situation when Jackie returns to Earth? (Ages in this problem refer to biological ages-that is,how much time has passed for each sister since she was born. )

Accepted Answer

A) It's the year 2050,and both twin sisters are 70 years old. 
B) It's the year 2050.Gwen (who stayed home)is 70 years old,but Jackie is only a little older than her age of 20 when she left. 
C) It's the year 2050.Gwen is 70 years old.Jackie is 19. 
D) It's the year 2100.Gwen and Jackie are both 120 years old. 
E) According to Gwen,Jackie returns to Earth in the year 2050,but according to Jackie,she returns in the year 2001. 
A) It's the year 2050,and both twin sisters are 70 years old. 
B) It's the year 2050.Gwen (who stayed home)is 70 years old,but Jackie is only a little older than her age of 20 when she left. 
C) It's the year 2050.Gwen is 70 years old.Jackie is 19. 
D) It's the year 2100.Gwen and Jackie are both 120 years old. 
E) According to Gwen,Jackie returns to Earth in the year 2050,but according to Jackie,she returns in the year 2001.

Question 17

Ben is racing a light beam in a 100-meter dash.Ben bursts out of the starting blocks at 99 percent of the speed of light (0.99c).At the same instant,a flashlight beam is turned on from the starting blocks.
-Refer to the race described above.According to Ben,what happens?

Accepted Answer

A) The light beam gradually pulls ahead of him and wins the race because it is going 1 percent of the speed of light faster than him. 
B) The light beam instantly finishes the race,before Ben even has a chance to start. 
C) The light beam moves out ahead of him at the full speed of light,winning the race easily. 
D) Ben wins the race and becomes a hero. 
A) The light beam gradually pulls ahead of him and wins the race because it is going 1 percent of the speed of light faster than him. 
B) The light beam instantly finishes the race,before Ben even has a chance to start. 
C) The light beam moves out ahead of him at the full speed of light,winning the race easily. 
D) Ben wins the race and becomes a hero.

Question 18

Bob is coming toward you at a speed of 75 km/hr.You throw a baseball in his direction at 75 km/hr.What does he see the ball doing?

Accepted Answer

A) He sees the ball coming at him at 75 km/hr. 
B) He sees the ball going away from him at 75 km/hr. 
C) He sees the ball coming at him at 150 km/hr. 
D) He sees the ball going away from him at 150 km/hr. 
E) He sees the ball remaining stationary. 
A) He sees the ball coming at him at 75 km/hr. 
B) He sees the ball going away from him at 75 km/hr. 
C) He sees the ball coming at him at 150 km/hr. 
D) He sees the ball going away from him at 150 km/hr. 
E) He sees the ball remaining stationary.

Question 19

You and Mae are in free-float frames.Mae has just passed you,traveling at a speed of 60 km/hr.You throw a ball toward her at a speed of 60 km/hr.What will Mae see the ball doing?

Accepted Answer

A) She'll see the ball coming toward her at 60 km/hr. 
B) The ball will be stationary,floating freely in her own reference frame. 
C) She'll see the ball moving away from her at 60 km/hr. 
D) She'll see the ball coming toward her at 120 km/hr. 
A) She'll see the ball coming toward her at 60 km/hr. 
B) The ball will be stationary,floating freely in her own reference frame. 
C) She'll see the ball moving away from her at 60 km/hr. 
D) She'll see the ball coming toward her at 120 km/hr.

Question 20

Tom is going to your left at 90% of the speed of light and Joan is going to your right at 90% of the speed of light.What will Tom say about you and Joan?

Accepted Answer

A) You are moving away from him at 90% the speed of light.Joan is moving away from him at 180% of the speed of light. 
B) You are moving away from him at 90% the speed of light.Joan is moving away from him at as speed that is faster than 90% of the speed of light,but slower than the whole speed of light. 
C) You are moving away from him at 90% the speed of light.Joan is moving away from him at as speed of light. 
D) You and Joan are both moving away from him at 90% the speed of light. 
A) You are moving away from him at 90% the speed of light.Joan is moving away from him at 180% of the speed of light. 
B) You are moving away from him at 90% the speed of light.Joan is moving away from him at as speed that is faster than 90% of the speed of light,but slower than the whole speed of light. 
C) You are moving away from him at 90% the speed of light.Joan is moving away from him at as speed of light. 
D) You and Joan are both moving away from him at 90% the speed of light.

Exam 26: Space and Time

Shawn is traveling away from you at a speed of 120 km/hr.He throws a baseball that,according to him,is going at 100 km/hr in your direction.What do you see the ball doing?

Ben is racing a light beam in a 100-meter dash.Ben bursts out of the starting blocks at 99 percent of the speed of light (0.99c).At the same instant,a flashlight beam is turned on from the starting blocks. -How does the explosion of a nuclear bomb provide evidence of the theory of relativity?

You are in an airplane,traveling relative to the ground at 500 km/hr.You throw a baseball toward the front of the plane at a speed of 50 km/hr.How fast would someone on the ground say the baseball is moving?

You are racing away from Earth in a super spaceship in which you can continually increase your speed.Which of the following best explains how people on Earth will perceive your speed?

What is the primary reason why scientists accept the idea that the speed of light is the same for everyone?

Bob is in a spaceship going by you at 90% of the speed of light,but in an upright standing position.Bob measures his mass to be 50 kg,his height to be 2.0 meters,and his waist size to be 80 cm.What would you say about his measurements?

Different observers can disagree about the speed of a baseball,but they cannot disagree about the speed of a light beam.

Use the appropriate relativity formula given in the text to answer the following: Isabella is moving by you at a speed of 0.8c.While 1 minute passes on your watch,how much time will you see pass on her watch?

How does the explosion of a nuclear bomb provide evidence for the theory of relativity?

Which of the following is not true of the special theory of relativity?

Which of the following is not a prediction made by the theory of relativity?

How would we view time (clocks)on the spaceship as it goes by?

You take a trip to a star located 1,000 light-years away and return.You travel at an average speed of 0.99c. HINT: The time dilation formula is: t′=1−(vc)2t t^{\prime}=\sqrt[t]{1-\left(\frac{v}{c}\right)^{2}} t′=t1−(cv​)2​ -About how many years will pass on Earth while you are gone?

Julia is traveling away from you at 0.95c when she shoots a probe forward from her spacecraft.According to her,the probe travels at 0.8c.How fast do you see the probe going?

Which of the following correctly describes the situation when Jackie returns to Earth? (Ages in this problem refer to biological ages-that is,how much time has passed for each sister since she was born. )

Ben is racing a light beam in a 100-meter dash.Ben bursts out of the starting blocks at 99 percent of the speed of light (0.99c).At the same instant,a flashlight beam is turned on from the starting blocks. -Refer to the race described above.According to Ben,what happens?

Bob is coming toward you at a speed of 75 km/hr.You throw a baseball in his direction at 75 km/hr.What does he see the ball doing?

You and Mae are in free-float frames.Mae has just passed you,traveling at a speed of 60 km/hr.You throw a ball toward her at a speed of 60 km/hr.What will Mae see the ball doing?

Tom is going to your left at 90% of the speed of light and Joan is going to your right at 90% of the speed of light.What will Tom say about you and Joan?

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Light and Matter: Reading Messages from the Cosmos

Telescopes: Portals of Discovery

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Formation of the Solar System

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Jovian Planet Systems

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Other Planetary Systems: The New Science of Distant Worlds

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You take a trip to a star located 1,000 light-years away and return.You travel at an average speed of 0.99c. HINT: The time dilation formula is: $t^{\prime}=\sqrt[t]{1-\left(\frac{v}{c}\right)^{2}}$ -About how many years will pass on Earth while you are gone?