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PH103 PRINCIPLES OF PHYSICS III practice 2011
EXAM III – FINAL EXAM
All work on this exam must be your own. You may use a calculator, instructor handouts, and an 8½”x11” sheet of
notes. Clearly indicate your final answer for each question.
PART I ATOMIC, NUCLEAR, PARTICLE
Section 1: Multiple choice. (2 pts each) No partial credit will be given for this section. Circle only one answer for
each question.
1.
2.
3.
4.
5.
A particle made up of the quark combination uus is a ___ with a charge of ___.
a.
meson, 0
b.
meson, +1
c.
baryon, 0
d.
baryon, +1
The mu-neutrino is affected by which of the fundamental forces?
a.
strong only
b.
gravity and weak only
c.
gravity and strong only
d.
gravity, weak, and electromagnetic
One rem of alphas does ___ tissue damage as/than one rem of betas. One rad of alphas does ___ tissue
damage as/than one rad of betas.
a. more, the same
b.
less, the same
c.
the same, more
d.
more, less
There are ___ different leptons, ___ different quarks, and ___ different gauge bosons.
a.
3, 3, 6
b.
6, 6, 6
c.
3, 3, 4
d.
6, 6, 4
The charge of the particle emitted in alpha decay is __, and the charge of the particle emitted in gamma
decay is __.
a. 0, 0
b.
0, -1
c.
+2, 0
d.
6.
7.
8.
9.
+2, -1
226
Ra decays to 222Rn when it undergoes
a.
alpha decay
b.
beta-minus decay
c.
beta-plus decay
d.
gamma decay
Which of the following is not currently accepted to be an elementary particle?
a.
proton
b.
neutrino
c.
photon
d.
tau
The energy of an electron at rest far away from anything (and thus not interacting) is __ an electron bound in
an atom.
a. greater than
b.
less than
c.
equal to
d.
depends on the atomic energy level
If the orbital angular momentum quantum number is 7, then the principle quantum number must be an
integer
a. <7
b.
<7
c.
>7
d.
>7
10. If hypothetic force A is mediated by a particle with mass M, and hypothetic force B is mediated by a particle
with mass 2M, then
a. hypothetic force B will be twice as strong as hypothetic force A.
b.
hypothetic force B will be half as strong as hypothetic force A
c.
hypothetic force B will have twice the range of hypothetic force A
d.
hypothetic force B will have half the range of hypothetic force A
11. True or false: Mass is conserved.
a.
True; the total mass of a closed system remains constant
b.
True; the total mass plus antimass of a closed system remains constant
c.
False; mass can be converted to or from other forms of energy
d.
False; mass can be converted to or from antimatter
12. Nuclide A has a decay constant that is 4 times the decay constant of nuclide B. The half-life of nuclide A is
__ the half-life of nuclide B.
a.
¼
b.
½
c.
2 times
d.
4 times
13. The W+ is affected by which of the fundamental forces?
a.
gravity and electromagnetic only
b.
gravity and weak only
c.
gravity and strong only
d.
gravity, weak, and electromagnetic
14. A nucleus of 31Cl contains ___ protons and ___ neutrons
a.
31, 31
b.
17, 14
c.
14, 31
d.
14, 17
15. An electron and positron are headed for a head-on collision in the lab. The electron has a velocity of +0.3 c
relative to the lab, and the positron has a velocity of -0.3 c relative to the lab. The velocity of the electron
relative to the positron is
a.
negative and greater than 0.3 in magnitude
b.
negative and less than 0.3 in magnitude
c.
positive and greater than 0.3 in magnitude
d.
positive and less than 0.3 in magnitude
16. In this question, "mass" means rest mass not relativistic mass. A proton has
a)
wavelength and frequency, but no mass or energy.
b)
mass and energy, but no wavelength or frequency.
c)
wavelength, frequency, and energy but no mass.
d)
wavelength, frequency, energy, and mass.
17. The lens of your eye forms
a.
a real upright image.
b.
a real inverted image.
c.
a virtual upright image.
d.
a virtual inverted image.
18. An electron currently has a momentum of 100 MeV/c. If the electron's speed is doubled it will have a
momentum of
a.
100 MeV/c
b.
more than 100 MeV/c, but less than 200 MeV/c.
c.
200 MeV/c.
d.
more then 200 MeV/c.
Section 2: Long-answer problems and questions. Partial credit will be given for this section. Show all work and
justify all answers.
11. The + particle is a baryon. It has one strange quark, no charm, top, or bottom quarks.
a) What specific combination of quarks makes up the +? (Don’t forget to justify.)
b) Find the wavelength of each of two photons produced if a + and its antiparticle, each having kinetic
energy 200MeV, annihilate.
12. A sample of 24Na initially contains 2X1015 nuclei.
a)
Find the initial activity of the sample in Bq.
b) Find the binding energy of a neutral atom of 24Na in MeV.
c)
Can the binding energy be negative? Why or why not?
13. A hydrogen atom’s electron is in the 4p state.
a)
Determine the energy of the electron.
b) Determine the magnitude of the angular momentum of the electron.
c)
Determine the wavelength of light absorbed, if the electron jumps to the 5s state.
14. Find the wavelength of a non-relativistic proton that has 2eV of kinetic energy.
15. Oprah Winfrey takes a trip to a planet 3 light-years away at a speed of 0.8 c.
a.
How long does the trip take according to her fans on Earth?
b.
How long does the trip take according to Oprah?
16. A simple magnifier is used by a person with a nearpoint of 10 cm. When they are viewing an image with a
relaxed eye, the angular magnification is 13.
a.
An angular magnification of 13 means the angular size of the image is 13 times as big as what? (No
justification required for this part)
b.
Find the maximum angular magnification this person can achieve with this magnifier.
CONSTANTS AND CONVERSION FACTORS: