Physics 102-001 Homework #4 with Extra Credit (23 Points Possible)

Physics 102-001 Homework #4 with extra credit (23 points possible) Due date: 3 May 2012 (but you can turn it in earlier)

Name: ______

1) Light is emitted from an atom when one of its electrons A) is boosted to a higher energy level. B) makes a transition to a lower energy level. C) neither of these

2) Which color of light carries the most energy per photon? A) red B) green C) blue D) violet E) all the same

3) An atom that emits a certain frequency of light is A) not likely to absorb that same frequency. B) an absorber of the same frequency.

4) A certain object emits infrared waves. If it were to emit visible light waves instead, its temperature would have to be A) higher B) lower. C) the same, temperature doesn't make any difference.

5) The energy of a photon depends on its A) speed B) frequency C) amplitude D) all of these E) none of these

6) The photoelectric effect best demonstrates the A) wave nature of light. B) particle nature of light. C) both of these D) none of these

7) A beam of electrons has A) wave properties. B) particle properties. C) both of these D) neither of these

8) When Rutherford had a stream of alpha particles hit a gold foil, most of the particles A) bounced back. B) went almost straight through. C) stopped. D) spiraled.

9) X-rays are similar to A) alpha rays. B) beta rays. C) gamma rays. D) all of these E) none of these

10) Which radiation has no electric charge associated with it? A) alpha rays B) beta rays C) gamma rays D) all of these

11) A quark is A) an elementary particle. B) a building block of nucleons. C) a building block of hadrons. D) all of these E) none of these

12) The atomic number of an element is the same as the number of its A) protons. B) neutrons. C) nucleons. D) neither of these

13) The half-life of an isotope is one day. At the end of two days the amount that remains is A) none. B) one-half. C) one-quarter. D) one-eighth. E) none of these 14) Most of the radioactivity we personally encounter comes from A) fallout from past and present testing of nuclear weapons. B) nuclear power plants. C) medical X rays. D) the natural environment.

15) When radium (A = 88) emits an alpha particle, the resulting nucleus has atomic number A) 86. B) 88. C) 90. D) 92. E) none of these

16) In bubble chambers and other types of particle detectors, there is a magnetic field present, and many of the particles leave tracks that are curved. This indicates A) They are undergoing interference B) They have a non-zero electric charge B) They came from outside the Earth’s atmosphere

17) In the fissioning of uranium, a chain reaction is caused by A) the enormous energy release. B) the kinetic energy of the decay products. C) ejected neutrons. D) the conversion of mass to energy. E) none of these

18) The experiments of Michelson and Morley provided evidence that the speed of light is A) invariant. B) the same whether its source approaches or recedes. C) constant. D) all of these E) none of these

19) According to the special theory of relativity, all laws of nature are the same in reference frames that A) accelerate. B) move in circles. C) move at constant velocity. D) oscillate. E) none of these

20) According to the well-known equation, energy equals mass times the speed of light squared A) mass and energy travel at the speed of light squared. B) energy is actually mass traveling at the speed of light squared. C) mass and energy travel at twice the speed of light. D) mass and energy are related. E) none of these

21) Compared to clocks in a stationary reference frame, clocks in a moving reference frame run A) slower. B) faster. C) at the same speed.

22) A woman standing on the ground sees a rocket ship move past her at 95% of the speed of light. Compared to when the rocket is at rest, the woman measures the rocket's length as A) longer. B) shorter. C) the same length.

23) According to the principle of equivalence A) mass and energy are two forms of the same thing. B) space and time are two forms of the same thing. C) electricity and magnetism are two forms of the same thing. D) observations made in an accelerating reference frame are indistinguishable from those made in a gravitational field. E) all of these