Waves-Princeton AP Physics I

Doppler Effect

When a source of sound waves and a detector are not in relative motion, the frequency that the source emits matches the frequency that the detector receives.

Nodes

always alternate with antinodes, they're equally spaced, and the distance between two successive nodes (or antinodes) is equal to 1 /2λ.

Crests

the maximum vertical displacement above the horizontal

Mechanical wave

disturbance transmitted by a medium form from one point to another, without the medium itself being transported

Crests

maximum vertical displacement above the horizontal

Troughs

maximum vertical displacement below the horizontal

Wavelength

the crests and troughs repeat themselves at regular intervals along the rope, and the distance between two adjacent crests (or two adjacent troughs) is the length of one wave

Amplitude of the wave

maximum displacement from the horizontal equilibrium position of the rope is measurable

period

The time it takes for one complete vertical oscillation of a point on the rope

Frequency

the number of cycles it completes in one seconds, f

Constructive Interference

two waves have a displacement of the same sign when they overlap, and the combined wave will have a displacement of greater magnitude than either individual wave

Destructive Interference

the waves have opposite displacements when they meet, the combined waveform will have a displacement smaller magnitude than either individual wave

standing wave

a wave in which the ratio of its instantaneous amplitude at one point to that at any other point does not vary with time

Compressions

The variations in the conducting medium can be positions at which the molecules of the medium are bunched together (where the pressure is above normal)

Rarefactions

positions where the pressure is below normal