Physics 2210, Practice Final Exam, Fall 2012
Name________________________________ A#______________________________
Closed Book, Notes, Etc., No calculators. Points are out of 200. Problems 1-36 are worth 4 each Problems 37-41 are
worth 11 each. Problem 42 is worth 10 extra credit points. Name is worth 1. Enter 1-36 on scantron sheets.
1. The derivative of x2 is
a. x
b. 2x3
c. 2x ☻
d. x3/3
e. None of the above
2. The derivative of eax is
a. aeax ☻
b. axeax
c. (eax)/
d. eax
e. None of the above
3. The derivative of cos(kx) is
a. ksin(kx)
b. –ksin(kx) ☻
c. kcos(kx)
d. –kcos(kx)
e. None of the above
4. a(x+y)=
a. ax+ay ☻
b. ax+y
c. x+ay
d. (x+y)/a
e. None of the above
5. (x/a)/(y/b)=
a. xy/(ab)
b. bx/(ay) ☻
c. ab/(xy)
d. ax/(by)
e. None of the above
6. Solve for x: x+a = y+b
a. y+a+b
b. ay+b
c. y+b-a ☻
d. by+a
e. None of the above
7. ∫x2dx =
a. (x3)/3 +const ☻
b. 2x+const
c. x2/2 + const
d. x/2 + const
e. None of the above
8. If a/x = b/y then x =
a. a/b
b. ay/b ☻
c. b/ay
d. aby
e. None of the above
T
B
mg
θ
A
For problems 9, 10, and 11 refer to the figure above.
Assume a coordinate system with origin at A, x axis horizontal and positive to the right, and y axis vertical and
positive up. The beam has no mass and is pined at A. T is the tension in the horizontal cable and is a positive scalar
quantity. m, g, and L are also positive scalars.
9. The vertical force the pin at A exerts on the beam is
a. mgj ☻
b. –mgj
c. Tj
d. –Tj
e. None of the above
10. The horizontal force that the pin at A exerts on the beam is
a. mgi
b. –mgi
c. Ti ☻
d. –Ti
e. None of the above
11. The tension T equals in magnitude
a. mg
b. mg cos θ
c. mg sin θ
d. mg tan θ ☻
e. None of the above
Referring to problems 12 and 13: A girl standing with outstretched arms on a frictionless rotation table holds two
masses in her hands and is spinning with angular velocity ω. The moment inertia of girl plus masses is I. The girl
then pulls in the two masses and her angular velocity increases to 4ω.
12. What is the final angular momentum of the system?
a. 4Iω
b. 2Iω
c. Iω ☻
d. Iω/2
e. Iω/4
13. What is the final moment of inertia of the system?
a. 4I
b. 2I
c. I
d. I/2
e. I/4
☻
14. The efficiency of a Carnot heat engine operating between 100 K and 200 K is
a. 1.
b. ½
☻
c. ¼
d. 0.2
e. None of the above
16. In which of the following processes is temperature held constant?
a. Adiabatic
b. Isobaric
c. Isovolumetric
d. Isothermal
☻
e. None of the above
17. The SI units of ∫pdV are
a. Joules
☻
b. Newtons
c. Watts
d. kgm2
e. None of the above
18. If action and reaction force pairs are equal and opposite, why don't they simply cancel out when acting on a
single object?
a. Because they are never of the same type.
b. Because they are never exactly equal.
c. Because they never act on the same object.
☻
d. Because there are cases where the Third Law is invalid.
e. None of the above.
19. Static frictional force
a. is always less than moving frictional force for the same system
b. is always μN
c. always depends upon the velocity of a sliding body
d. can be between zero and μN.
☻
e. None of the above
20. In a Carnot engine during which of the following processes does heat enter or leave the system?
a. Adiabatic
b. Isothermal
☻
c. Isobaric
d. Isovolumetric
e. None of the above
24. Which of the following pairs have the same SI units?
a. velocity and acceleration
b. force and work
c. kinetic energy and torque
☻
d. linear and angular momentum
e. None of the above.
25. Whether or not angular momentum is conserved for two objects attracted to each other
a. depends upon how you define the system.
☻
b. depends upon whether or not energy is conserved.
c. depends upon whether or not internal torques are involved.
d. None of the above.
26. If the net work done by all forces on an 8-kg mass initially at rest is 4 J what is the final velocity of the mass in
m/s?
a. 4
b. 2
c. 1
☻
d. ½
e. None of the above
27. In our scheme, mass, length, time, and charge
a. are defined in terms of other defined quantities.
b. are not defined in any sense.
c. cannot be measured in SI units
d. are measured in comparison with a standard
☻
e. None of the above
28. The weakest fundamental force is
a. electromagnetic.
b. nuclear.
c. gravitational.
☻
d. frictional.
e. None of the above.
29. Which one of the following conservation laws can be considered a tautology ("A phrase or expression in which
the same thing is said twice in different words.")?
a. Linear momentum.
b. Angular momentum.
c. Energy.
☻
d. None of the above.
30. Two sirens at rest are being tuned so that the frequencies are coming closer. The beat frequency is
a. increasing
b. decreasing.
☻
c. staying the same.
d. None of the above.
31. If you double the temperature of a black body the radiated energy is increased by what factor?
a. 16
☻
b. 8
c. 4
d. 2
e. None of the above.
32. The wavelength of a violin string of length L vibrating in its lowest possible frequency is
a. 4L
b. 2L ☻
c. L
d. L/2
e. None of the above.
33. Temperature is a measure of
a. Heat transferred from one body to another
b. The Second Law of Thermodynamics
c. The entropy of a system
d. The mean kinetic energy of the random motion of molecules.
☻
e. None of the above.
34. Which of the two vector quantities referred to an object in uniform circular motion are parallel. r is measured
from the center of the circle. v=dr/dt. a=dv/dt.
a. r and a.
☻
b. r and v.
c. v and a.
d. None of the above
35. The expression r=R[icos(ωt)+jsin(ωt)] where r is measured from the origin of a fixed coordinate system does
not refer to uniform circular motion if
a. ω varies with time
☻
b. R is constant
c. i and j are perpendicular
d. ω is measured in radians per second.
e. None of the above.
36. Which is a specific application but not a general statement.
a. Uat b with respect to a =-Wgoing from a to b if forces are conservative
b. U=mgh
☻
c. U=-GMm/r
d. W=∫F•dr
e. None of the above
38. Two identical balls of mass m are heading directly toward each other, one with velocity vi and the other with
velocity -vi. They collide and rebound with velocities –vi/2 and vi/2:
a. What is the initial total momentum?
zero
b. What is the final total momentum?
zero
c. What is the initial total kinetic energy?
mv2
d. What is the final total kinetic energy?
mv2/2
e. Was momentum conserved?
yes
f. Was mechanical energy conserved and, if not, where did the energy go? no, into heat.
39. a. Determine the temperature of two moles of an ideal gas of volume 1 m3 and pressure 2 Pa. Take R to be 8
J/K. (Give number and units). b. If the gas undergoes an isothermal expansion to 2 m3, what will be the new
pressure? a. T=1/8 K b. 1 Pa.
40. A 0.040 kg mass is attached to a spring and undergoes simple harmonic motion. Its maximum acceleration is
15 m/s2 and its maximum speed is 3 m/s. Determine the (a) angular frequency and (b) spring constant.
a. ω=5rad/s b. k=1 N/m.