Chapter 19 Vibrations and Waves Flashcards
Sine curve
The waveform traced by simple harmonic motion, which can be made visible on a moving conveyor belt by a pendulum swinging at right angles above the moving belt.
Amplitude
For a wave or vibration, the maximum displacement on either side of the equilibrium (midpoint) position.
Wavelength
The distance between successive crests, troughs, or identical parts of a wave.
Frequency
For a vibrating body or medium, the number of vibrations per unit time. For a wave, the number of crests that pass a particular point per unit time.
Hertz
The SI unit of frequency. One hertz (symbol Hz) equals one vibration per second.
Period
The time in which a vibration is completed. The period of a wave equals the period of the source, and is equal to 1/frequency.
Wave speed
The speed with which waves pass a particular point: Wave speed = wavelength x frequency
Transverse wave
A wave in which the medium vibrates in a direction perpendicular (transverse) to the direction in which the wave travels. Light waves and water waves are transverse.
Longitudinal wave
A wave in which the medium vibrates in a direction parallel (longitudinal) to the direction in which the wave travels. Sound waves are longitudinal.
Interference pattern
The pattern formed by superposition of different sets of waves that produces reinforcement in some places and cancellation in others.
Standing wave
A stationary wave pattern formed in a medium when two sets of identical waves pass through the medium in opposite directions.
Doppler effect
The shift in received frequency due to motion of a vibrating source toward or away from a receiver.
Bow wave
The V-shaped disturbance created by an object moving across a liquid surface at a speed greater than the wave speed.
Shock wave
The cone-shaped disturbance created by an object moving at supersonic speed through a fluid.
Sonic boom
The loud sound resulting from the incidence of a shock wave.
