Conceptual Physics Chapter 25 Key Terms

period

(a)The time required for a complete orbit (b) The time required for a pendulum to make one to-and-fro swing, In general, the time required to comete a single cycle

shock wave

A cone-shaped wave produced by an object moving at supersonic speed through a fluid

sine curve

A curve whose shape represents the crests and troughs of a wave, as a traced out by a swinging pendulum that drops a trail of sand over a moving conveyor belt

red shift

A decrease in the measured frequency of light (or other radiation) from a receding source; called the red shift because the decrease is toward the low-frequency, or red, end of the color spectrum

wave

A disturbance that repeats regularly in space and time and that is transmitted progressibely from one place to the next with no actual transport of matter

interference pattern

A pattern formed by the overlapping of two or more waves that arrive in a region at the same time

longitudinal wave

A wave in which the vibration is in the same direction as that in which the wave is traveling, rather than right angles to it

transverse wave

A wave with vibration at right angles to the direction the wave is traveling

constructive interferance

Addition of two or more waves when wave crests overlap to produce a resulting wave of increased amplitude

blue shift

An increase in the measured frequency of light from an approaching source; called the blue shift because the apparent increase is toward the high-frequency, or blue, end of the color spectrum. Also occurs when an observer approaches a source

vibration

An oscillation, or repeating back-and-forth motion, about an equilibrium position

node

Any part of a standing wave that remains stationary

destructive interferance

Combination of waves where crests of one wave overlap troughs of another resulting in a wave of decreased amplitude

crest

One of the places in a wave where the wave is highest or the dusturbance is greatest

trough

One of the places in a wave where the wave is lowest, or the disturbance is greatest, in the opposite direction from a crest

in phase

Term applied to two or more waves whose crests (and troughs) arrive at one place at the same time so that their effects reinforce each other

out of phase

Term applied to two waves for which the crest of one wave arrives at a point at the same time that a trough of the second wave arrives. Their effects cancel each other

hertz

The SI unit of frequency. One herts (Hz) is one cycle per second.

bow wave

The V-shaped wave produced by an object moving on a liquid surface faster than the wave speed

Doppler effect

The apparent change in frequency of a wave due to the motion of the source or of the receiver

simpe harmonic motion

The back-and-forth vibratory motion of a swinging pendulum

amplitude

The distance from the midpoint to the maximun (crest) of a wave or, equivalently, from the midpoint to the maximun (trough)

wavelength

The distance from the top of the crest of a wave to the top of the following crest, or equivalently, the distance between succcessive identical parts of the wave

frequency

The number of events (cycles, vibrations, oscillations, or any repeated event) per time; measured in herts (or even per time) Inverse of period

antinodes

The positions on a standing wave where the largest amplitude occur

sonic boom

The sharp crack heard when the shock wave that sweeps behind a supersonic aircraft reaches the listener

standing wave

Wave in which parts of the wave remaing stationary and the wave appears not to be traveling. The result of interferance between an incident (original) wave and a reflected wave