Download Physics: Practice Problems for Final

Honors Physics: Practice Problems for Final
Try any of these that seem to be unfamiliar.
(Answers are given in parentheses so that you may check
your work.)
1. Running at 2.0 m/s, Bruce, the 45.0 kg quarterback,
collides with Biff, the 90.0 kg tackle, who is traveling at 7.0
m/s in the other direction. Upon collision, Biff continues to
travel forward at 1.0 m/s. How fast and in what direction is
Bruce knocked? (10. m/s backwards)
2. A shotputter heaves a 7.26 kg shot with a final velocity of
7.50 m/s. What is the kinetic energy of the shot? (204 J)
3. A 6500 kg freight car traveling at 2.5 m/s collides with an
8000.kg stationary freight car. If they interlock upon
collision, find their velocity. (1.1 m/s)
4. A rock climber wears a 7.50 kg knapsack while scaling a
cliff. After 30.0 min, the climber is 8.20 m above the
starting point.
a) How much work does the climber do on the
knapsack? (603 J) b) If the climber weighs 645 N, how much
work does she do lifting herself and the knapsack? (5890 J)
c) What is the average power developed by the climber? (3.27 W)
5. Radio station WBOS broadcasts at a frequency of 92.9 MHz.
What is the wavelength of the radio waves emitted by WBOS?
(3.23 m)
6. A periodic transverse wave that has a frequency of 10.0 Hz
travels along a string. The distance between a crest and
either adjacent trough is 2.50 m. What is the wavelength?
7. A wave generator produces 16.0 pulses in 4.00 s. a) What
is its period? b) What is its frequency? (0.250 s, 4.00 Hz)
8. What is the wavelength of a sound wave that has a frequency
of 250.Hz and a speed of 350.m/s? What is the air temperature?
(1.40 m, 31ºC)
9. If the distance between two masses is quadrupled, what
happens to the gravitational force between them?
10. Two bowling balls each have a mass of 6.8 kg. They
are located next to one another with their centers 21.8 cm
apart. What gravitational force do they exert on each
other? (6.5 X 10-8 N)
11. What would be the period of a 20.06 cm pendulum on
Earth? How long would a pendulum on the moon have to be to
have the same period? (0.8989 s, .03343 m)
12. If the distance between two point charges is reduced
to one-third, what happens to the electrostatic force
between them?
13. Two charges are separated by a distance and exert a
force on each other. What new force will exist if the
magnitude of each of the charges is doubled?
14. Two point charges are separated by 10.0 cm. If one
charge is +20.00 C and the other is –6.00 C, what is the
force between them? (-1.10 X 102 N)
15. What is the resistance of the heating element in a car
lock de-icer that contains a 1.5 V battery supplying a
current of 0.5 A to the circuit? (3 Ω)
16. How much power is used by a contact lens heating unit
that draws 0.070 A of current from a household line?(8.4 W)
17. Three resistors (6.0 Ω, 10. Ω, 15 Ω) are connected in
series to a 12 V battery. Draw the circuit diagram. Find
the total current in the circuit, the voltage drop across
each resistor and the current through each resistor. (0.39
A; 2.3 V, 3.9 V, 5.8 V; 0.39 A)
18. The same resistors are now connected in parallel.
Answer the same questions as above. (4.0 A; 12 V; 2.0 A,
1.2 A, 0.80 A)
19. A projectile is launched at 33m/s at an angle of 20.º
to the ground. How long is it in the air? What is its
maximum height and range, neglecting air resistance and
assuming it lands on ground the same height as that from
which it was launched? (2.3 s, 6.5 m, 71 m)
20. The mass of a bicycle and rider is 53.0 kg. How much
work has been done if the bicyclist slows the bicycle from
a speed of 3.84 m/s to 1.27 m/s? (-348 J)
21. A 0.068 kg ball strikes a wall with a velocity of 22.1
m/s. The wall stops the ball in 0.36 s. What is the
magnitude of the impulse on the ball?
does the wall exert to stop the ball?
What magnitude force
(1.5 N.s, 4.2 N)
22. What work is done when 3.0 C is moved through an
electric potential difference of 1.5 V? (4.5 J) If the
potential difference is between two parallel plates that
are 0.20 mm apart, what is the magnitude of the electric
field between them? (7.5 X 103 N/C)
Additional topics (from students F06)
23. At 10.0ºC, a pipe open at both ends produces a fifth
harmonic standing wave of frequency 500. Hz. What is the
length of the pipe? (1.69 meters; LA)
24. At 20.0ºC, a tube opened at one end but closed at the
other is 2.00 meters long. What frequency is produced by
the third harmonic? (129 Hz; LA)
25) A large block of wood with a mass of 10.2kg is hanging
from two cords. A bullet with a mass of 9.62grams is shot
at the block of wood. When the two collide the bullet gets
stuck inside of the wood and the entire structure swings to
rise to a height of 6.81cm above its resting position. What
was the speed of the bullet prior to hitting the block of
wood?
(1130 m/s; DK)
26) If two tuning forks of frequencies of 256 Hz and 260 Hz
were played, how many beats would be heard, and at what
frequency?
(4 beats, 258 Hz ; CT)
27) A boat moves toward the shore at 42.0 m/s. The boat
sounds a horn with a frequency of 261 Hz. What frequency is
detected by a stationary observer standing on the beach?
(297 Hz; CD)