PHY 102 Exam I Review

A heavy brass ball is used to make a pendulum with a period of 5.5 s. How long is the cable that connects the pendulum ball to the ceiling? (Assume the cable’s mass is negligible compared to the ball’s.)

• 4.7 m

• 6.2 m

• 7.5 m

• 8.7 m

Answer explanation

The figure represents the motion of a mass on a spring. What is approximately the frequency of this oscillation?

• 0.08 Hz

• 0.04 Hz

• 0.02 Hz

• 0.01 Hz

Answer explanation

A spring has an unstretched length of 20 cm. A 100 g mass hanging from the spring stretches it to an equilibrium length of 30 cm. Suppose the mass is pulled down to where the spring’s length is 40 cm. When it is released, it begins to oscillate. What is approximately the frequency of the oscillation? (SHOW YOUR WORK)

• 0.10 Hz
• 0.62 Hz

• 1.6 Hz

• 10 Hz

Answer explanation

At approximately which of these times does the kinetic energy have its maximum value?

• 0 s

• 8 s

• 13 s

• 26 s

Answer explanation

A ball of mass m oscillates on a spring with spring constant k = 200 N/m. The ball’s position is x = (0.350 m) cos(15.0 t) with t measured in seconds. What is approximately the frequency of the ball’s motion?

• 0.35 Hz

• 2.39 Hz

• 5.44 Hz

• 6.28 Hz

Answer explanation

A 0.20 kg mass on a horizontal spring is pulled back a certain distance and released. The maximum speed of the mass is measured to be 0.28 m/s. If, instead, a 0.40 kg mass were used in this same experiment, the maximum speed would be: (SHOW YOUR WORK)

• 0.14 m/s

• 0.20 m/s

• 0.28 m/s

• 0.40 m/s

Answer explanation

The figure shown is a graph of the lower leg angle versus time in an experiment. What is approximately the time constant here?

• 0.25 s

• 1.10 s

• 2.51 s

• 3.40 s

Answer explanation

Two strings of different linear density are joined together and pulled taut. A sinusoidal wave on these strings is traveling to the right, as shown in the figure. When the wave goes across the boundary from string 1 to string 2, the frequency is unchanged. What happens to the velocity?

• The velocity increases.

• The velocity stays the same.

• The velocity decreases.

Answer explanation

An AM radio listener is located 5.0 km from the radio station. If he is listening to the radio at the frequency of 660 kHz, how many wavelengths fit in the distance from the station to his house? (SHOW YOUR WORK)

• 11

• 22

• 33

• 132

Answer explanation

Many species of bats find flying insects by emitting pulses of ultrasound and listening for the reflections. Some bats utilize a sound pulse with a rapidly decreasing frequency. A decreasing-frequency pulse has

• Decreasing wavelength.

• Decreasing speed.

• Increasing wavelength.

• Increasing speed.

Answer explanation