1998 Physics Quiz Bowl (1-20)

1. Which of the following is not a vector quantity?
A. acceleration
B. electric field
C. energy
D. force
E. velocity

2. An observer hears a sound with frequency 400 hz. Its wavelength is approximately

A. 0.85 m
B. 1.2 m
C. 2.75 m
D. 13.6 m
E. 44 m

3. An object in equilibrium has three forces, F₁ of 30 N, F₂ of 50 N, and F₃ of 70 N, acting on it. The magnitude of the resultant of F₁ and F₂ is

A. 10 N
B. 20 N
C. 40 N
D. 70 N
E. 80 N

4. As sound travels from steel into air, both its speed and its:

A. wavelength increase.
B. wavelength decrease.
C. frequency increase.
D. frequency decrease.
E. frequency remain unchanged.

5. Which of the following temperatures would be most appropriate to keep milk at inside a refrigerator?

A. -200 C
B. 5 K
C. 400 C
D. 278 K
E. 350 K

6. When any four resistors are connected in parallel, the _____ each resistor is the same.

A. charge on
B. current through
C. power from
D. resistance of
E. voltage across

7. A heat engine takes in 200 J of thermal energy and performs 50 J of work in each cycle. What is its efficiency?

A. 500%
B. 400%
C. 25%
D. 20%
E. 12%

8. When two charged point-like objects are separated by a distance R, the force between them is F. If the distance between them is quadrupled, the force between them is

A. 16F
B. 4F
C. F
D. F/4
E. F/16

9. An electroscope is given a positive charge, causing its foil leaves to separate.

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When an object is brought near the top plate of the electroscope, the foils separate even further. We could conclude

A. that the object is positively charged.
B. that the object is electrically neutral.
C. that the object is negatively charged.
D. only that the object is charged.
E. only that the object is uncharged.

10. A charged particle with constant velocity enters a uniform magnetic field whose direction is parallel to the particle's velocity. The particle will

A. speedup.
B. slowdown.
C. experience no change in velocity.
D. follow a parabolic arc.
E. follow a circular arc.

11. In the nuclear reaction ^⁶_₃Li + ? ® ^⁷_₃Li the "?" represents

A. an alpha particle
B. a deuteron
C. an electron
D. a neutron
E. a proton

12. An alpha particle is the same as

A. a helium nucleus
B. a positron
C. an electron
D. a high energy photon
E. a deuteron

13. When a falling object moves with terminal velocity, it

A. has zero velocity.
B. has zero acceleration.
C. has an upward acceleration.
D. is no longer subject to air resistance.
E. has an acceleration of approximately 10 m/sec²

14. How long must a 2.5 m/s² acceleration act to change the velocity of a 2.0-kg object by 3.0 m/s?

A. 0.83 sec
B. 1.2 sec
C. 1.7 sec
D. 2.5 sec
E. 7.5 sec

15. A freely falling object is found to be moving downward at 18 m/s. If it continues to fall, two seconds later the object would be moving with a speed of

A. 8.0 m/s
B. 10 m/s
C. 18 m/s
D. 38 m/s
E. 180 m/s

16. If the unit for force is F, the unit for velocity v, and the unit for time T, then the unit for momentum is

A. FT
B. FTv
C. FT² v
D. FT / v
E. Fv / T

17. Which diagram best represents what happens to a ray of light entering air from water? Air is at the top in all diagrams.

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18. When a train is at rest, both a passenger on the train and a ticket seller on the station agree that the trains whistle produces sound at a frequency of 120 Hz. When the train is moving away from the station at 15 m/s, the passenger hears a frequency of ______ Hz and the ticket seller hears a frequency of ____ Hz.

A. 120, 125
B. 115, 120
C. 120, 120
D. 115, 115
E. 120, 115

19. In order to produce an enlarged, upright image of an object, you could use a

A. converging lens more than one focal length from the object.
B. converging lens less than one focal length from the object.
C. diverging lens more than one focal length from the object.
D. diverging lens exactly one focal length from the object.
E. diverging lens less than one focal length from the object.

20. Wire I and wire II are made of the same material. Wire II has twice the diameter and twice the length of I. If I has resistance R, II has resistance

A. R/8
B. R/4
C. R/2
D. R
E. 2R