Waves Test Review

Reading: Ch. 14 p.p. 380-395, Ch. 15 p.p. 402-423

Topics: Wave Characteristics, Wave Behaviors, Sound Waves

Labs & Activities: Waves Lab, Sound on Computers, Palm Pipes, Speed of Sound Lab,

Equations: v = d v = f λ T = 1 f = v f = v fbeat = f2 – f1

t f 2L 4L

  • Know how waves are produced and how they travel.
  • Be able to use the relationship between frequency, wavelength, and wave speed.
  • Be able to use the relationship between frequency and period.
  • Know how waves interfere.
  • Be able to draw an interference pattern.
  • Know how waves behave at a boundary.
  • Know what a sound wave is and how it transmits energy.
  • Know how the computer interface interprets sound waves with a microphone.
  • Know what a beat frequency is.
  • Know what bow waves and sonic booms are.
  • Recognize how frequency and pitch change due to the Doppler Effect.
  • Be able to interpret standing wave patterns and to determine the wavelength and frequency of the waves. (tubes & strings)
  1. Describe what type of wave sound is and how a sound wave travels through air. Be sure to describe the direction the air molecules move and the direction the wave travels.
  1. Which types of materials transmit sound the fastest and why?

Use the diagram shown to answer questions 3-5.

  1. What is the wavelength of the wave shown?
  1. What is the amplitude of the wave shown?
  1. What is the frequency if the wave speed is 20 m/s?
  1. A nurse counts 76 heartbeats in one minute. What are the period and frequency of the heart’s oscillations or beats?
  1. A light wave travels through the air at a speed of 3 x 10⁸ m/s. If red light has a wavelength of 6.6 x 10⁻⁷ m, what is the frequency of this light?
  1. Knowing that the speed of sound in air is 343 m/s and the limits of human hearing are 20 Hz to 20,000 Hz, find the range of wavelengths a typical person hears.
  1. A captain of a ship sounds his horn and hears an echo after 3.0 seconds. How far away is the barrier that the sound is reflecting off?
  1. One end of a string is fixed to a wall. A transverse wave pulse is sent through the string. Compare the incident pulse to the reflected pulse.
  1. A hawk is flying directly away from a bird watcher. The hawk produces a shrill cry. Explain how the bird watcher perceives the sound and why.
  1. A tuning fork of 442 Hz is held next to a tuning fork of unknown frequency. If 12 beats are counted in 3 seconds, what are the possible frequencies of the other tuning fork?
  1. A rubber band is stretched and fixed at both ends so it cannot move. It has a fundamental frequency of 440 Hz and a length of 0.1 m. What is the speed at which waves travel on the rubber band?
  1. A 0.2 m glass is one quarter full of water. If air travels at 343 m/s, what frequency sound is heard when someone strikes the top side of the glass gently? How would the sound change if some of the water was poured out?
  1. A 1.51 m string vibrates at a fundamental frequency of 158 Hz. What is the frequency and wavelength of the string’s third harmonic?
  1. Determine the pattern produced when the following wave pulses completely overlap.