Return to PHYS 151 Exam & Answers page
Entirely Multiple-Choice (on bubble sheet):
unit conversions:
1. D 3.8x10^14 micrometers
2. E 9100 kPa
3. C 22,400 cm^3
4. A 3.3x10^-7 kg*m^2
5. B sqrt(2) (K = (1/2)mv^2)
6. E 85 kJ (W = mgh)
7. D 430 W (P=W/t)
8. E 4.0 m/s (use conservation of momentum)
9. B inelastic (40 J of kinetic energy is lost
in collision)
10. A (net torque = I * ang.accel.)
11. C (either center-of-mass at 50-cm position OR
net torque about pivot = 0)
12. A 0.0027 m/s^2 (g = GM/r^2)
13. C (a_rad = v^2/r; ang.veloc. = constant,
so ang.accel. = 0)
14. D (period does not depend on mass of [small]
satellite)
15. E (I = MR^2; T^2 = (4pi^2/GM)*r^3; L=mvr
& v^2=GM/r)
16. E 589 N (normal force = mg + ma, and
a=0)
17. E 829 N (normal force = mg + ma, and a=4)
18. C 349 N (normal force = mg + ma, and a=-4)
19. D 12 m/s ( v(8s) = v(5s) + a*(t since 5s)
)
20. A 0 m/s
21. B 18 m ( y(8s) = y(5s) + v(5s)*(t since
5s) + (1/2)*a*(t since 5s) )
22. D (Newton's 3rd Law: both F and impulse are
equal & opposite. Newton's 2nd Law: a = F/m --- masses unequal,
so accelerations unequal)
23. E (use conservation of momentum)
24. A (use conservation of energy: kinetic is converted
to elastic-potential)
25. A (formula for period of mass-on-spring)
26. A (F = ma and F = -kx)
27. B 29 N (vector addition - triangle method
is fast in this case)
28. D 51 N
29. A 3.6 m/s (use trig to find monkey starts
at height of 0.670, then use conservation of energy)
30. C 4.5 s (use formula for period of pendulum)
31. D (tension = weight + centripetal force = mg
+ mv^2/r)
32. C (vines must hold more weight, therefore have
greater tensions)
33. B (conservation of energy in #29 shows: v at
bottom depends only on starting height, NOT on mass)
34. B (period of pendulum in #30 does NOT depend
on mass of pendulum bob)
35. B (use conservation of energy)
36. B (amplitude diminishes as energy is lost; period
of pendulum in #30 does NOT depend on amplitude of swings)
37. C 1 L of water is heaviest (all four
weights are: 1N, 0.981N, 9.81N, and 0.981N)
38. C (object floats if its density is less than
density of fluid)
39. D 3.52 km (at depth h, P = density*g*h)
40. T 5.32x10^8 N (F = P*A)
41. D Doppler Effect
42. B Beats
43. A Archimedes's Principle
44. C Bernoulli's Principle
45. E 14 m (wavelength = v / f)
46. E 75 m/s (wavelength of fundamental = 2L
& v = wavelength * f)
47. E 125 Hz (4th overtone = 5th harmonic;
f_5 = 5 * f_1)
48. D (speed depends on tension, and frequency depends
on speed; wavelength depends only on L)
49. B (transverse waves have amplitude of wave's
displacement perpendicular to direction of wave travel)
50. C
51. E 773 Hz (wavelength = (4/3)*L &
f = v / wavelength)
52. D 4.186 kJ (100 mL is 100 g of water;
Q = m*c*(delta T) )
53. A (solid = left-hand region, liquid = upper-right
region, vapor = lower-right region)
54. B (no -- at 75K, substance is vapor below 0.5
atm)
55. B (at 2 atm, boiling point is approx. 340 K)
56. E 490 degC (P1/T1 = P2/T2, and convert
temps to kelvins)
57. A (W = P*(delta V), and here V does not change)
58. A ( (delta U) = Q - W; #57 says that W=0,
and question says that heat Q is added, so (delta U) > 0 )
59. B (adiabatic means that Q=0, but question says
that heat Q is added)
60. A 29.2% (e = (Q_H - Q_L) / Q_H)
61. C 328 degC (e = (T_H - T_L) / T_H, and
convert temps to kelvins)