Question 1

An electron (m = 9.11*10-31 kg) has a speed of 0.95c. Its kinetic energy is:

Accepted Answer

A)  8.2 * 10-14 J 
B)  1.8*10-13 J 
C)  2.0 * 10-13 J 
D)  2.2* 10-13 J 
E)  2.6* 10-13 J 
A)  8.2 * 10-14 J 
B)  1.8*10-13 J 
C)  2.0 * 10-13 J 
D)  2.2* 10-13 J 
E)  2.6* 10-13 J B

Question 2

A source at rest emits light of wavelength 500 nm. When it is moving at 0.90c away from an observer, the observer detects light of wavelength:

Accepted Answer

A)  26 nm 
B)  115 nm 
C)  500 nm 
D)  2200 nm 
E)  9500 nm 
A)  26 nm 
B)  115 nm 
C)  500 nm 
D)  2200 nm 
E)  9500 nm D

Question 3

A rocket traveling with constant velocity makes an 8.4 * 1015 m trip in 1 year. The proper time between events which mark the beginning and end of the trip is:

Accepted Answer

A)  0.21 years 
B)  0.46 years 
C)  1.0 years 
D)  2.2 years 
E)  4.7 years 
A)  0.21 years 
B)  0.46 years 
C)  1.0 years 
D)  2.2 years 
E)  4.7 years B

Question 4

As a rocket ship moves by at 0.95c a mark is made on a stationary axis at the front end of the rocket and 9.0 * 10-8 s later a mark is made on the axis at the back end. The marks are 100 m apart. The rest length of the rocket is:

Accepted Answer

A)  31 m 
B)  78 m 
C)  100 m 
D)  240 m 
E)  320 m 
A)  31 m 
B)  78 m 
C)  100 m 
D)  240 m 
E)  320 m

Question 5

Two independent events occur 100 m apart with an intervening time interval of 0.42$\mu$s. The proper time between the events is:

Accepted Answer

A)  0 $\mu$s 
B)  0.16 $\mu$s 
C)  0.26$\mu$s 
D)  0.42 $\mu$s 
E)  0.69 $\mu$s 
A)  0 $\mu$s 
B)  0.16 $\mu$s 
C)  0.26$\mu$s 
D)  0.42 $\mu$s 
E)  0.69 $\mu$s

Question 6

A console lamp in the cabin of a spaceship appears green when the ship and observer are both at rest. When the ship is moving at 0.90c away from Earth, passengers on board see:

Accepted Answer

A)  a dark lamp (the frequency is too high to be seen) 
B)  a dark lamp (the frequency is too low to be seen) 
C)  a red lamp 
D)  a violet lamp 
E)  a green lamp 
A)  a dark lamp (the frequency is too high to be seen) 
B)  a dark lamp (the frequency is too low to be seen) 
C)  a red lamp 
D)  a violet lamp 
E)  a green lamp

Question 7

According to the theory of relativity:

Accepted Answer

A)  moving clocks run fast 
B)  energy is not conserved in high speed collisions 
C)  the speed of light must be measured relative to the ether 
D)  momentum is not conserved in high speed collisions 
E)  none of the above 
A)  moving clocks run fast 
B)  energy is not conserved in high speed collisions 
C)  the speed of light must be measured relative to the ether 
D)  momentum is not conserved in high speed collisions 
E)  none of the above

Question 8

As we watch, a spaceship passes us in time $\Delta$t. The crew of the spaceship measures the passage time and finds it to be $\Delta$t'. Which of the following statements is true?

Accepted Answer

A)  $\Delta$t is the proper time for the passage and it is smaller than $\Delta$t' 
B)  $\Delta$t is the proper time for the passage and it is greater than $\Delta$t' 
C)  $\Delta$t' is the proper time for the passage and it is smaller than $\Delta$t 
D)  $\Delta$t' is the proper time for the passage and it is greater than $\Delta$t 
E)  None of the above statements are true. 
A)  $\Delta$t is the proper time for the passage and it is smaller than $\Delta$t' 
B)  $\Delta$t is the proper time for the passage and it is greater than $\Delta$t' 
C)  $\Delta$t' is the proper time for the passage and it is smaller than $\Delta$t 
D)  $\Delta$t' is the proper time for the passage and it is greater than $\Delta$t 
E)  None of the above statements are true.

Question 9

A clock is moving along the x axis at 0.6c. It reads zero as it passes the origin (x = 0). When it passes the x = 180 m mark on the x axis the clock reads:

Accepted Answer

A)  0.60 $\mu$s 
B)  0.80 $\mu$s 
C)  1.00 $\mu$s 
D)  1.25 $\mu$s 
E)  1.67 $\mu$s 
A)  0.60 $\mu$s 
B)  0.80 $\mu$s 
C)  1.00 $\mu$s 
D)  1.25 $\mu$s 
E)  1.67 $\mu$s

Question 10

The mass of a particle is m. In order for its total energy to be twice its rest energy, its momentum must be:

Accepted Answer

A)    
B)    
C)  mc 
D)    
E)  2 mc 
A)    
B)    
C)  mc 
D)    
E)  2 mc

Question 11

The spaceship U.S.S. Enterprise, traveling through the galaxy, sends out a smaller explorer craft that travels to a nearby planet and signals its findings back. The proper time for the trip to the planet is measured by clocks:

Accepted Answer

A)  on board the Enterprise 
B)  on board the explorer craft 
C)  on Earth 
D)  at the center of the galaxy 
E)  none of the above 
A)  on board the Enterprise 
B)  on board the explorer craft 
C)  on Earth 
D)  at the center of the galaxy 
E)  none of the above

Question 12

An electron (m = 9.11 * 10-31 kg) has a momentum of 1.3 *10-21 kg .m/s. Its kinetic energy is:

Accepted Answer

A)  6.3 *10-14 J 
B)  8.2 * 10-14 J 
C)  1.5 *10-13 J 
D)  3.2 * 10-13 J 
E)  4.0 *10-13 J 
A)  6.3 *10-14 J 
B)  8.2 * 10-14 J 
C)  1.5 *10-13 J 
D)  3.2 * 10-13 J 
E)  4.0 *10-13 J

Question 13

Light from some stars shows an apparent change in frequency because of:

Accepted Answer

A)  interference 
B)  refraction by layers of air 
C)  diffraction 
D)  reflection 
E)  relative motion 
A)  interference 
B)  refraction by layers of air 
C)  diffraction 
D)  reflection 
E)  relative motion

Question 14

A train traveling very fast (v = 0.6c) has an engineer (E) at the front, a guard (G) at the rear and a passenger (S') exactly half way between them. Both E and G are equipped with yellow signaling lamps. The train passes a station, closely observed by the station master (S). Both E and G use their lamps to send signals. According to both S and S' these signals arrive simultaneously at the instant S' is passing S. According to S, the signal from E will look ______ and that from G will look _____:

Accepted Answer

A)  red, blue 
B)  yellow, yellow 
C)  blue, red 
D)  blue, blue 
E)  red, red 
A)  red, blue 
B)  yellow, yellow 
C)  blue, red 
D)  blue, blue 
E)  red, red

Question 15

According to the theory of relativity:

Accepted Answer

A)  mass is a form of energy 
B)  moving particles lose mass 
C)  momentum is not conserved in high speed collisions 
D)  a rod moving rapidly sideways (perpendicular to its length) is shorter along its length 
E)  a rod moving rapidly sideways (perpendicular to its length) is longer along its length 
A)  mass is a form of energy 
B)  moving particles lose mass 
C)  momentum is not conserved in high speed collisions 
D)  a rod moving rapidly sideways (perpendicular to its length) is shorter along its length 
E)  a rod moving rapidly sideways (perpendicular to its length) is longer along its length

Question 16

If the mass of a particle is zero its speed must be:

Accepted Answer

A)  c 
B)  infinite 
C)  0 
D)  any speed less than c 
E)  any speed greater than c 
A)  c 
B)  infinite 
C)  0 
D)  any speed less than c 
E)  any speed greater than c

Question 17

Light from a stationary spaceship is observed, then the spaceship moves directly away from the observer at high speed. As a result, the light seen by the observer has:

Accepted Answer

A)  a higher frequency and a longer wavelength than before 
B)  a lower frequency and a shorter wavelength than before 
C)  a higher frequency and a shorter wavelength than before 
D)  a lower frequency and a longer wavelength than before 
E)  the same frequency and wavelength as before 
A)  a higher frequency and a longer wavelength than before 
B)  a lower frequency and a shorter wavelength than before 
C)  a higher frequency and a shorter wavelength than before 
D)  a lower frequency and a longer wavelength than before 
E)  the same frequency and wavelength as before

Question 18

Two flashes of light occur simultaneously at t = 0 in reference frame S, one at x = 0 and the other at x = 600 m. They are observed in reference frame S', which is moving at 0.95c in the positive x direction. The origins of the two frames coincide at t = 0 and the clocks of S' are zeroed when the origins coincide. In S' the coordinate where the leading edges of the two light flashes meet and the time when they meet are:

Accepted Answer

A)  300 m, 1.0 $\mu$s 
B)  15 m, 0.050 $\mu$s 
C)  585 m, 1.95 $\mu$s 
D)  48 m, 0.16 $\mu$s 
E)  1900 m, 0.16 $\mu$s 
A)  300 m, 1.0 $\mu$s 
B)  15 m, 0.050 $\mu$s 
C)  585 m, 1.95 $\mu$s 
D)  48 m, 0.16 $\mu$s 
E)  1900 m, 0.16 $\mu$s

Question 19

Two events occur 100 m apart with an intervening time interval of 0.60 $\mu$s. The speed of a reference frame in which they occur at the same coordinate is:

Accepted Answer

A)  0 c 
B)  0.25c 
C)  0.56c 
D)  1.1c 
E)  1.8c 
A)  0 c 
B)  0.25c 
C)  0.56c 
D)  1.1c 
E)  1.8c

Question 20

Two isotopes of hydrogen fuse to form a helium nucleus and a neutron: 2H + 3H → 4He + n
The masses are:
  What is the Q value of this reaction?

Accepted Answer

A)  1.9 MeV 
B)  2.5 MeV 
C)  2.8 MeV 
D)  17.6 MeV 
E)  938 MeV 
A)  1.9 MeV 
B)  2.5 MeV 
C)  2.8 MeV 
D)  17.6 MeV 
E)  938 MeV

Exam 37: Relativity

An electron (m = 9.11*10-31 kg) has a speed of 0.95c. Its kinetic energy is:

A source at rest emits light of wavelength 500 nm. When it is moving at 0.90c away from an observer, the observer detects light of wavelength:

A rocket traveling with constant velocity makes an 8.4 * 1015 m trip in 1 year. The proper time between events which mark the beginning and end of the trip is:

As a rocket ship moves by at 0.95c a mark is made on a stationary axis at the front end of the rocket and 9.0 * 10-8 s later a mark is made on the axis at the back end. The marks are 100 m apart. The rest length of the rocket is:

Two independent events occur 100 m apart with an intervening time interval of 0.42 μ\muμ s. The proper time between the events is:

A console lamp in the cabin of a spaceship appears green when the ship and observer are both at rest. When the ship is moving at 0.90c away from Earth, passengers on board see:

According to the theory of relativity:

As we watch, a spaceship passes us in time Δ\DeltaΔ t. The crew of the spaceship measures the passage time and finds it to be Δ\DeltaΔ t'. Which of the following statements is true?

A clock is moving along the x axis at 0.6c. It reads zero as it passes the origin (x = 0). When it passes the x = 180 m mark on the x axis the clock reads:

The mass of a particle is m. In order for its total energy to be twice its rest energy, its momentum must be:

The spaceship U.S.S. Enterprise, traveling through the galaxy, sends out a smaller explorer craft that travels to a nearby planet and signals its findings back. The proper time for the trip to the planet is measured by clocks:

An electron (m = 9.11 * 10-31 kg) has a momentum of 1.3 *10-21 kg .m/s. Its kinetic energy is:

Light from some stars shows an apparent change in frequency because of:

According to the theory of relativity:

If the mass of a particle is zero its speed must be:

Light from a stationary spaceship is observed, then the spaceship moves directly away from the observer at high speed. As a result, the light seen by the observer has:

Two events occur 100 m apart with an intervening time interval of 0.60 μ\muμ s. The speed of a reference frame in which they occur at the same coordinate is:

Two isotopes of hydrogen fuse to form a helium nucleus and a neutron: 2H + 3H → 4He + n The masses are: What is the Q value of this reaction?

Measurement

Motion Along a Straight Line

Vector

Motion in Two and Three Dimensions

Force and Motion I

Force and Motion II

Kinetic Energy and Work

Potential Energy and Conservation of Energy

Center of Mass and Linear Momentum

Rotation

Rolling, Torque, and Angular Momentum

Equilibrium and Elasticity

Gravitation

Fluids

Oscillations

Waves I

Waves II

Temperature, Heat, and the First Law of Thermodynamics

The Kinetic Theory of Gases

Entropy and the Second Law of Thermodynamics

Electric Charge

Electric Fields

Gauss Law

Electric Potential

Capacitance

Current and Resistance

Circuits

Magnetic Fields

Magnetic Fields Due to Currents

Induction and Inductance

Electromagnetic Oscillations and Alternating Current

Maxwells Equations; Magnetism of Matter

Electromagnetic Waves

Images

Interference

Diffraction

Photons and Matter Waves

More About Matter Waves

All About Atoms

Conduction of Electricity in Solids

Nuclear Physics

Energy From the Nucleus

Quarks, Leptons, and the Big Bang

Filters

An electron (m = 9.11*10^-31 kg) has a speed of 0.95c. Its kinetic energy is:

A rocket traveling with constant velocity makes an 8.4 * 10¹⁵ m trip in 1 year. The proper time between events which mark the beginning and end of the trip is:

As a rocket ship moves by at 0.95c a mark is made on a stationary axis at the front end of the rocket and 9.0 * 10^-8 s later a mark is made on the axis at the back end. The marks are 100 m apart. The rest length of the rocket is:

Two independent events occur 100 m apart with an intervening time interval of 0.42 $\mu$ s. The proper time between the events is:

As we watch, a spaceship passes us in time $\Delta$ t. The crew of the spaceship measures the passage time and finds it to be $\Delta$ t'. Which of the following statements is true?

An electron (m = 9.11 * 10^-31 kg) has a momentum of 1.3 *10^-²¹ kg .m/s. Its kinetic energy is:

Two events occur 100 m apart with an intervening time interval of 0.60 $\mu$ s. The speed of a reference frame in which they occur at the same coordinate is:

Two isotopes of hydrogen fuse to form a helium nucleus and a neutron: ²H + ³H → ⁴He + n The masses are: What is the Q value of this reaction?