chapter 12: relativity

Question 1

which of the following quantities do not depend on velocity?

Answer 1

m0

Question 2

a particle travels at the speed of light. we conclude that (be careful, only one answer is correct)

Answer 2

the rest mass is 0

Question 3

in everyday life, we don’t see the effects of relativity because

Answer 3

they are too small to detect easily

Question 4

in the twin effect, the traveling twin is

Answer 4

younger

Question 5

Neutrinos are believed to have mass

Answer 5

small, but not zero

Question 6

Tachyons are particles that

Answer 6

travel faster than c

Question 7

the photon has a rest mass approximately equal to

Answer 7

0

Question 8

a moving object is

Answer 8

shorter and younger

Question 9

if muller discovers a new, energetic particle (the “mulleron”) that has zero mass, then we can conclude that the mulleron

Answer 9

travels at the speed of light

Question 10

which of the following is not a zero-mass particle

Answer 10

beta-ray

Question 11

tachyons

Answer 11

have never been observed

Question 12

The speed of a massless particle

Answer 12

is the same to all observers

Question 13

When a particle approaches the speed of light, its mass approaches

Answer 13

infinity

Question 14

identify which are the particles that pass easily through the earth

Answer 14

neutrinos

Question 15

the lorentz contraction says that a football thrown past your face

Answer 15

is shorter by a factor of gamma

Question 16

the observation of neutrino decay proves that

Answer 16

neutrinos do have mass

Question 17

A neutron can have which of the following values for its energy

Answer 17

Either of the preceding two values

Question 18

An astronaut Alice makes a round trip at 3/5 the speed of light. Her twin Bob stays on the Earth. When Alice returns, Bob is

Answer 18

older than alice

Question 19

A radioactive particle has a half-life of 1 second. If it moves at 3/5 the speed of light, it’s new half-life will be

Answer 19

5/4 seconds

Question 20

The lorentz contraction refers to the fact that

Answer 20

moving objects get slower

Question 21

Jim and Mary are both from Berkeley and are the exact same age. Jim travels at a velocity of 65 miles per hour to Los Angeles and waits there. Mary drives the next day at 70 mph. When she gets to Los Angeles, who is older?

Answer 21

Jim

Question 22

If one person travels at 99% the speed of light for 7 years, how much younger will he be than his identical twin who didn’t travel?

Answer 22

6 years

Question 23

The most accurate equation for energy is

Answer 23

E=mc^2

Question 24

Jane and Tom synchronize their watches on Earth. Jane remains on the Earth while Tom takes a round-trip to Pluto at near light speed. When they get back together, whose clock is correct?

Answer 24

both clocks are correct

Question 25

We measure that a particle travels at the speed of light. We conclude that

Answer 25

It's rest mass is zero

Question 26

When the velocity of an object with rest mass m0 approaches the speed of light, its energy approaches

Answer 26

Infinity

Question 27

When a person moves at a velocity near the speed of light, which of the following are true - compared to a person at rest?

Answer 27

He doesn't age as rapidly His mass increases His energy increases

Question 28

If you travel at 50% of the speed of light, your mass is increased by a factor of

Answer 28

1.15

Question 29

According to relativity theory, the energy of an object of mass m0 that is moving at velocity v is

Answer 29

ym0c^2

Question 30

As the velocity of a moving object approaches the speed of light, what happens to its energy?

Answer 30

it goes to infinity

Question 31

Electrons cannot go as fast as light because

Answer 31

it would take infinite energy

Question 32

At very high speed, all of these change except

Answer 32

electric charge

Question 33

The effects of special relativity must be taken into account for

Answer 33

GPS

Question 34

If the velocity is (12/13)c, then the gamma function is

Answer 34

13/5

Question 35

When the velocity of a proton is half of the speed of light, then the gamma function is approximately equal to

Answer 35

1.15

Question 36

When a radioactive rock travels near the speed of light, its mass

Answer 36

increases and there are fewer decays