Download test 3 practice

test 3 practice
Multiple Choice
Identify the choice that best completes the statement or answers the question.
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1. A space probe has an 18.0-m length when measured at rest. What length does an observer at rest measure
when the probe is going by at a speed of 0.700 c?
a. 25.2 m
b. 12.9 m
c. 12.6 m
d. 9.18 m
____
2. An earth observer sees a spaceship at an altitude of 980 m moving downward toward the earth at a speed of
0.800 c. What is the spaceship's altitude as measured by an observer in the spaceship?
a. 1 630 m
b. 1 270 m
c. 893 m
d. 588 m
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3. From a stationary position, I observe a moving boxcar, which has a mirror along the front wall, but it is open
at the back of the boxcar. I send a flash of light from my flashlight and time the flash of light as it goes to the
front of the boxcar and returns to the back of the boxcar. A passenger in the boxcar also times the round trip
of the flash of light. Previously I had measured the time required for the round trip of a flash of light when the
boxcar was stationary, and I call this the stationary time. Which two times are the same?
a. the time recorded on my watch and the previous stationary time
b. the time recorded on the passenger's watch and the previous stationary time
c. the time recorded on my watch and the time recorded on the passenger's watch
d. None of the times are the same.
____
4. A boxcar without a front or a back is moving toward the right. Two flashes of light move through the boxcar,
one moving from back to front toward the right, the other moving from front to back toward the left. A
passenger in the boxcar records how long it takes each flash of light to pass from one end of the boxcar to the
other end. According to the passenger, which took longer?
a. the flash going from back to front
b. the flash going from front to back
c. They both took the same time.
d. It depends on whether the passenger is sitting at the front or the back of the boxcar.
____
5. A muon formed high in Earth’s atmosphere travels at a speed 0.990 0 c for a distance (as we see it) of 4 600
m before it decays. How far does the muon travel as measured in its frame?
a. 4 554 m
b. 2 596 m
c. 1 298 m
d. 649 m
____
6. An electron of mass 9.11 × 10−31 kg moves with a speed of 0.600 c. What is its momentum? (c = 3.00 × 108
m/s)
a. 1.34 × 10−22 kg⋅m/s
b. 2.05 × 10−22 kg⋅m/s
c. 4.12 × 10−22 kg⋅m/s
d. 6.03 × 10−22 kg⋅m/s
____
7. Including relativistic effects, doubling the speed of a object:
a. doubles its momentum.
b. more than doubles its momentum.
c. less than doubles its momentum.
d. has no effect on its momentum.
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8. At what speed must an object be moving in order that it has a kinetic energy 1.50 times its rest energy? (c =
3.00 × 108 m/s)
a. 1.91 × 108 m/s
b. 2.52 × 108 m/s
c. 2.75 × 108 m/s
d. 2.90 × 108 m/s
____
9. A spaceship, which has length 50 m and width 10 m when at rest, is moving in a direction along its length at a
speed where its length contraction results in a 40-m length measured by a stationary observer. What would the
measured width be in this case?
a. between 12 and 13 m
b. 10 m
c. 8 m
d. less than 8 m
____ 10. As the temperature of a radiation emitting blackbody becomes higher, what happens to the peak wavelength
of the radiation?
a. increases
b. decreases
c. remains constant
d. is directly proportional to temperature
____ 11. A quantum of radiation has an energy of 2.0 keV. What is its frequency? (h = 6.63 × 10−34 J⋅s and 1 eV = 1.60
× 10−19 J)
a. 3.2 × 1017 Hz
b. 4.8 × 1017 Hz
c. 6.3 × 1017 Hz
d. 7.3 × 1017 Hz
____ 12. What is the wavelength of a monochromatic light beam, where the photon energy is 3.00 eV? (h = 6.63 ×
10−34 J⋅s, c = 3.00 × 108 m/s, 1 nm = 10−9 m, and 1 eV = 1.6 × 10−19 J)
a. 311 nm
b. 414 nm
c. 622 nm
d. 1 243 nm
____ 13. An ultraviolet light beam having a wavelength of 130 nm is incident on a molybdenum surface with work
function of 4.2 eV. What is the stopping potential? (h = 6.63 × 10−34 J⋅s, c = 3.00 × 108 m/s, 1 eV = 1.6 × 10−19
J, and 1 nm = 10−9 m)
a. 1.3 V
b. 3.5 V
c. 5.4 V
d. 11.9 V
____ 14. Sources of red, blue, and yellow light each emit light with a power of 50 mW. Which source emits more
photons per second?
a. the red source
b. the blue source
c. the yellow source
d. They all emit the same number per second.
____ 15. Surface #1 has work function , and when bombarded with photons of wavelength
emits photoelectrons
with maximum energy
. Surface #2 has work function , and when bombarded by photons of
wavelength
emits photoelectrons with maximum energy
. If
, then which of the following
must be true?
a.
b.
c.
for surface #1 is greater than
for surface #2.
d.
for surface #2 is greater than
for surface #1.
____ 16. If a 1H nucleus, a 2H nucleus, and a 3H nucleus all had the same momentum, which one has the greatest de
Broglie wavelength?
a. 1H
b. 2H
c. 3H
d. All three have the same de Broglie wavelength.
____ 17. The Lyman series of hydrogen is made up of those transitions made from higher levels to n = 1. If the first
line in this series has a wavelength of 122 nm, what is the wavelength of the second line?
a. 49 nm
b. 103 nm
c. 364 nm
d. 486 nm
____ 18. The ionization energy for the hydrogen atom is 13.6 eV. What is the energy of a photon that is emitted as a
hydrogen atom makes a transition between the n = 4 and n = 2 states?
a. 0.85 eV
b. 2.55 eV
c. 3.40 eV
d. 6.80 eV
____ 19. Of the various wavelengths emitted from a hydrogen gas discharge tube, those that are associated with
transitions from higher levels down to the n = 1 level produce which of the following?
a. infrared
b. visible
c. mixture of infrared and visible
d. ultraviolet
____ 20. When an electron moves from the n = 1 to the n = 2 orbit:
a. both the radius and the angular momentum double.
b. both the radius and the angular momentum increase by a factor of 4.
c. the radius doubles and the angular momentum increases by a factor of 4.
d. the radius increases by a factor of 4, and the angular momentum doubles.
____ 21. The quantum number that can have only two possible values is the:
a.
b.
c.
d.
principal quantum number.
orbital quantum number.
orbital magnetic quantum number.
spin magnetic quantum number.
____ 22. The quantum mechanical model of the hydrogen atom suggests a visual picture of the electron as which of the
following?
a. raisin in pudding
b. probability cloud
c. planetary orbiting body
d. light quantum
____ 23. When a hydrogen atom absorbs a photon that raises it to the n = 4 state, how many different energies are
possible for the photon(s) that may be emitted as the atom eventually returns to the ground state?
a. 3
b. 4
c. 5
d. The correct answer is not given.
____ 24. When a hydrogen atom absorbs a photon that raises it to the n = 4 state, what is the greatest number of
photons that can be emitted by that atom as it returns to the ground state?
a. 3
b. 4
c. 5
d. The correct answer is not given.
____ 25. Consider the hydrogen atom, singly ionized helium atom, and the doubly ionized lithium atom. Arrange these
atoms from highest energy ground state to lowest energy ground state.
a. H, He+, Li++
b. Li++, He+, H
c. H, Li++, He+
d. Since each of these atoms has only one electron, they all have the same energy ground
state.
____ 26. If a hydrogen atom, originally in its ground state of energy –13.6 eV, absorbs a photon of energy 15.0 eV,
what is the resulting kinetic energy of the electron if the proton has negligible kinetic energy?
a. Such a photon cannot be absorbed in this case.
b. –1.4 eV
c. 1.4 eV
d. 15.0 eV
____ 27. Neglecting recoil of the gold nucleus, how much kinetic energy must an alpha particle (charge = 2 × 1.6 ×
10−19 C) have to approach to within 1.00 × 10−14 m of a gold nucleus (charge = 79 × 1.6 × 10−19 C)? (ke = 8.99
× 109 N⋅m2/C2 and 1 MeV = 1.6 × 10−13 J)
a. 11.7 MeV
b. 14.6 MeV
c. 18.2 MeV
d. 22.7 MeV
____ 28. An element is emitting alpha, beta, and gamma radiation. Rank order them in terms of the thickness of
protective shielding they will need for safety, from least to most.
a. alpha, beta and gamma
b. gamma, beta and alpha
c. beta, gamma and alpha
d. alpha, gamma and beta
____ 29. An ancient building was known to have been built 3 000 years ago. Approximately what proportion of
Carbon-14 atoms are yet in the building's wooden framing compared to the number which were present at the
time of its construction? (half life of 14C = 5 730 years)
a. 0.425
b. 0.500
c. 0.517
d. 0.696
____ 30. Approximately how many radioactive atoms are present in a tritium sample with an activity of 0.4 × 10−6 Ci
and a half-life of 12.3 years? (1 Ci = 3.7 × 1010 decays/s)
a. 1.3 × 108
b. 7 × 108
c. 3 × 1010
d. 8 × 1012
____ 31. Uranium-238 decays to Thorium-234 by emitting which of the following?
a. beta
b. alpha
c. gamma
d. positron
____ 32. A radioactive isotope that emits an alpha particle will change in what respect?
a. Atomic number decreases by four.
b. Mass number decreases by four.
c. Both choices a and b are valid.
d. None of the above choices are valid.
____ 33. An alpha particle (mass = 6.68 × 10−27 kg) is emitted from a radioactive nucleus with an energy of 5.00 MeV.
How fast is the alpha particle moving in m/s? (1 MeV = 1.6 × 10−13 J)
a. 2.40 × 107 m/s
b. 1.55 × 107 m/s
c. 3.70 × 106 m/s
d. 1.85 × 106 m/s
____ 34. Calculate the energy (in kW⋅h) given off if one kg of plutonium-239 undergoes complete fission. The energy
released per fission is 200 MeV. (1 MeV = 1.6 × 10−13 J)
a. 1.2 × 105 kW⋅h
b. 7.7 × 106 kW⋅h
c. 11 × 106 kW⋅h
d. 22 × 106 kW⋅h
____ 35. If there are 146 neutrons in 238U, how many neutrons are found in the nucleus of 235U?
a. 141
b. 143
c. 145
d. 147
____ 36. What energy must be added or given off in a reaction where two hydrogen atoms and two neutrons are
combined to form a helium atom? (Atomic masses for each: hydrogen, 1.007 825 u; neutron, 1.008 665 u;
helium, 4.002 602 u; also, 1 u = 931.5 MeV/c2)
a. 20.7 MeV added
b. 20.7 MeV given off
c. 28.3 MeV given off
d. 28.3 MeV added
____ 37. The binding energy of a nucleus is equal to:
a. the energy needed to remove one of the nucleons.
b. the average energy with which any nucleon is bound in the nucleus.
c. the energy needed to separate all the nucleons from each other.
d. the mass of the nucleus times c2.
____ 38. Calculate the binding energy per nucleon of the tritium nucleus,
, given that the mass of the tritium
nucleus is 3.016 05 u. (mp = 1.007 276 u, mn = 1.008 665, and 1 u = 931.5 MeV/c2)
a. 2.24 MeV/nucleon
b. 2.45 MeV/nucleon
c. 2.66 MeV/nucleon
d. 2.86 MeV/nucleon
____ 39. A radioactive material initially is observed to have an activity of 1 000 decays/sec. If three hours later it is
observed to have an activity of 125 decays/sec, what is its half-life?
a. 1/2 hour
b. 1 hour
c. 3 hours
d. 8 hours
____ 40. If a fossil bone is found to contain 1/8th as much Carbon-14 as the bone of a living animal, what is the
approximate age of the fossil? (half-life of 14C = 5 730 years)
a. 7 640 years
b. 17 200 years
c. 22 900 years
d. 45 800 years
____ 41. A pure sample of 226Ra contains 2.0 × 1014 atoms of the isotope. If the half-life of 226Ra = 1.6 × 103 years,
what is the activity of this sample?
a. 6.7 × 109 decays/yr
b. 8.7 × 1010 decays/yr
c. 9.4 × 1010 decays/yr
d. 13 × 1010 decays/yr
____ 42. Tritium has a half-life of 12.3 years. How many years will elapse when the radioactivity of a tritium sample
diminishes to 20% of its original value?
a. 21 years
b. 29 years
c. 57 years
d. 86 years
____ 43. The alpha emission process results in the daughter nucleus differing in what manner from the parent?
a. Atomic mass increases by one.
b. Atomic number decreases by two.
c. Atomic number increases by one.
d. Atomic mass decreases by two.
____ 44. A radioactive isotope that emits a gamma quantum will change in what respect?
a. Atomic number increases by one.
b. Atomic number decreases by one.
c. Atomic mass number decreases by one.
d. None of the above choices are valid.
____ 45. What particle is emitted when 20Na decays to 20Ne? (atomic numbers of Na and Ne are, respectively, 11 and
10)
a. alpha
b. beta (electron)
c. beta (positron)
d. gamma quantum
____ 46. The isotope 238U, which starts one of the natural radioactive series, decays first by alpha decay followed by
two negative beta decays. At this point, what is the resulting isotope?
a. 238U
b. 236U
c. 234Th (Z = 90 for Th.)
d. Some other uranium isotope not given above.
test 3 practice
Answer Section
MULTIPLE CHOICE
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29. ANS:
B
PTS: 1
DIF: 2
26.4 Consequences of Special Relativity
D
PTS: 1
DIF: 2
26.4 Consequences of Special Relativity
B
PTS: 1
DIF: 3
26.4 Consequences of Special Relativity
C
PTS: 1
DIF: 2
26.4 Consequences of Special Relativity
D
PTS: 1
DIF: 2
26.4 Consequences of Special Relativity
B
PTS: 1
DIF: 2
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B
PTS: 1
DIF: 2
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C
PTS: 1
DIF: 2
26.6 Relativistic Energy and the Equivalent of Mass and Energy
B
PTS: 1
DIF: 1
TOP:
B
PTS: 1
DIF: 1
27.1 Blackbody Radiation and Planck’s Hypothesis
B
PTS: 1
DIF: 2
27.1 Blackbody Radiation and Planck’s Hypothesis
B
PTS: 1
DIF: 2
27.2 The Photoelectric Effect and the Particle Theory of Light
C
PTS: 1
DIF: 2
27.2 The Photoelectric Effect and the Particle Theory of Light
A
PTS: 1
DIF: 1
27.2 The Photoelectric Effect and the Particle Theory of Light
D
PTS: 1
DIF: 2
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D
PTS: 1
DIF: 2
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B
PTS: 1
DIF: 2
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B
PTS: 1
DIF: 2
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D
PTS: 1
DIF: 2
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D
PTS: 1
DIF: 2
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D
PTS: 1
DIF: 1
28.4 Quantum Mechanics and the Hydrogen Atom
B
PTS: 1
DIF: 1
28.4 Quantum Mechanics and the Hydrogen Atom
C
PTS: 1
DIF: 2
TOP:
A
PTS: 1
DIF: 2
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A
PTS: 1
DIF: 2
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C
PTS: 1
DIF: 2
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D
PTS: 1
DIF: 3
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A
PTS: 1
DIF: 1
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D
PTS: 1
DIF: 2
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26.5 Relativistic Momentum
26.5 Relativistic Momentum
Conceptual Questions
Conceptual Questions
Conceptual Questions
28.3 The Bohr Model
28.3 The Bohr Model
28.3 The Bohr Model
28.3 The Bohr Model
28.7 Atomic Transitions and Lasers
28.7 Atomic Transitions and Lasers
Conceptual Questions
Conceptual Questions
29.1 Some Properties of Nuclei
29.3 Radioactivity
29.3 Radioactivity
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D
B
B
B
D
B
C
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C
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B
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D
C
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29.3 Radioactivity
29.4 The Decay Processes
29.4 The Decay Processes
29.4 The Decay Processes
30.1 Nuclear Fission
29.1 Some Properties of Nuclei
29.2 Binding Energy
29.2 Binding Energy
29.2 Binding Energy
29.3 Radioactivity
29.3 Radioactivity
29.3 Radioactivity
29.3 Radioactivity
29.4 The Decay Processes
29.4 The Decay Processes
29.4 The Decay Processes
29.5 Natural Radioactivity