PHY 112 - Make-Up Exam – Winter 2000

1. A particular metal rod stretches too much when a 2000 lb weight hangs from its end. Which characteristic of the rod could be too large?

a) ultimate strength b) cross-sectional area c) diameter d) length e) elastic modulus

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2-4. A large tank on top of a hill supplies water to the town below. The water level in the tank is 35 m above the faucet in Daisy Mae's bathtub.

2. When Daisy Mae's faucet is closed, the gauge pressure (not absolute pressure) acting on the inside of her faucet is _____ x 105 Pa.

a) 3.43 b) 4.44 c) 1.10 d) 2.42 e) 5.45

3. When Daisy opens the faucet completely and the water flows out frictionlessly, the water leaves the faucet with a speed of _____ m/s.

a) 33.0 b) 14.2 c) 22.0 d) 26.2 e) 29.8

4. Daisy likes to sit on a waterproof scale in her water-filled bathtub. When her feet and "seat" are on the scale and she isn't touching anything else, the scale reads only 490 N (110 lbs). When she stands on the scale before entering the tub, it reads a depressing 690 N (155 lbs). This means _____ m3 of Daisy must be beneath the water surface in the tub. (Hint: First find the buoyant force on Daisy?)

a) 0.02 b) 0.12 c) 0.07 d) 0.05 e) 0.005

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5. A PHY 112 student in Organic Chemistry Lab makes an orange colored blob which floats high in water. The mass density of the orange blob _____ 1000 kg/m3.

a) must be greater than b) cannot be equal to c) must equal

d) is greater than or equal to e) must be smaller than

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6-10. A 2 kg mass resting on a horizontal frictionless surface is attached to the end of a horizontal spring (k = 50 N/m). The mass is pulled horizontally and the spring stretches 0.1 m. When the mass is released it executes simple harmonic motion.

6. The acceleration of the mass the instant it is released is _____ m/s2.

a) 5 b) 0.4 c) 25 d) 2.5 e) .004

7. The frequency of the simple harmonic motion (in Hz) is

a) 1.3 b) 0.8 c) 31 d) 0.04 e) 4

8. The frequency of this oscillator will increase if the _____ increases.

a) maximum velocity b) period c) amplitude d) mass e) spring constant

9. The kinetic energy of the mass (in J) as it passes through the equilibrium position is

a) 0.02 b) 2.5 c) 1.0 d) 0.25 e) 25

10. Not true of this simple harmonic oscillator.

a) Net force acting on the mass is toward the equilibrium position.

b) Energy increases as amplitude increases.

c) Frequency increases as amplitude increases.

d) Time for a complete cycle remains constant.

e) Amplitude remains constant.

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11. The distance between successive crests on a wave is called the wave's

a) wavelength. b) amplitude. c) speed. d) frequency.

12. When a sound wave passes from air into water, its _____ is unchanged.

a) velocity b) amplitude c) frequency d) wavelength

13. You hear a 400 Hz sound from a train whistle traveling away from you at 33.33 m/s. The actual frequency of the whistle is _____ Hz.

a) 439 b) 365 c) 400 d) 443 e) 361

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14-15. You are trapped in a long narrow corridor closed off at both ends by the forces of the evil Empire. The even-more-evil Darth Vader sets up a standing wave with a wavelength of 16 m in the corridor in an attempt to "scramble your brains."

14. The smallest possible length of the corridor is _____ m. (Carefully think about what the question is asking.)

a) 4 b) 16 c) 12 d) 8 e) 32

15. The frequency of this standing wave is _____ Hz.

a) 43 b) 86 c) 29 d) 21 e) 11

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16. A plastic comb acquires a negative charge when you comb your hair. Your hair

a) acquires protons. b) loses protons. c) acquires electrons.

d) remains electrically neutral. e) loses electrons.

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17-19. A -5 micro-C charge and a +5 micro-C charge are 100 cm apart.

17. The electric field at the mid-point between them is _____ N/C.

a) 4.5 x 104 b) 3.6 x 105 c) 9 x 104 d) 1.8 x 105 e) 0

18. The electric potential at the mid-point is _____ V.

a) 9 x 104 b) 1.8 x 105 c) 0 d) 3.6 x 105 e) 4.5 x 104

19. At the mid-point, E _____ and V _____.

a) points to - charge, has no direction b) has no direction, points to - charge

c) points to + charge, has no direction d) points to - charge, points to - charge

e) has no direction, points to + charge

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20. What is the potential difference between two points if 0.58 J of work is needed to move 0.06 C of charge from one point to the other?