1. A wave of amplitude A destructively interferes with a wave of Amplitude B. How would you express their superposition mathematically?

a. A/B

b. A-B

c. A+B

d. A*B

2. Which statement/s best describes longitudinal waves in air? (Check all that apply)

a. The air molecules move perpendicular to the direction of the wave

b. The air molecules move in the same direction as the wave.

c. The air molecules do not move.

d. The air molecules move opposite the direction of the wave

3. Describe the sound produced by an instrument of length L, that is open at one end. Be sure to include the terms pitch, frequency, timbre, nodes and antinodes.

4. A fighter jet is coming straight at you and speeding up. Likely it is above you, so you should be safe. Describe how the sound wave from the fighter jet is changing in this situation. Use the words pitch, doppler, frequency, intensity, subsonic, and supersonic.

5. Which of the following are examples of resonance?

a. Organ pipes.

b. Gently tapping a drinking glass.

c. Swinging in a playground swing.

d. Running up and down the stairs.

6. Devise an experiment to test the acceleration due to gravity on the earth with a pendulum. Describe your experiment below and be sure to include the words period, oscillations, length, and equilibrium. Lastly, comment on how the acceleration would change on another planet.

7. Sound moves through air at a speed of 340 m/s. How long would it take to hear your echo in a canyon which is 50 meters away? Show all of your work with an explanation of your answer.

8. A fishing boat uses a sonar device which sends sound waves to the water that travel at 1000 m/s. The fishing boat detects a signal from a school of fish 1 second after the sonar signal leaves the boat. How far is the school of fish below the boat?