AP Physics 2: Unit 5 Variables

T

period: seconds per one cycle (s)

f

frequency: cycles per one second (Hz or s⁻¹)

A

amplitude: maximum vertical displacement from equilibrium (m)

λ

wavelength: distance from crest to crest (m)

Transverse wave

particles in the medium oscillate perpendicular to wave travel

Longitudinal wave

particles in the medium oscillate parallel to wave travel

d (waves)

distance between two slits (m)

D (waves)

path length: length between the boundaries of a wave medium (m)

y (waves)

distance between two spots in an interference pattern (m)

a (waves)

width of a single slit (m)

L (waves)

distance from a single slit to the screen (m)

n (waves)

harmonic number; the fundamental harmonic is written as n₁ or f₁.

Node

place(s) on a standing wave where the medium is not displacing/constantly at rest

Antinode

place(s) on a standing wave where the medium oscillates with maximum amplitude

Standing Wave Boundaries

closed/fixed ends are always nodes and open/free ends are always antinodes

Standing Wave Rules

- If the boundaries are the same, all harmonics can appear; n can be 1, 2, 3, 4...
- If the boundaries are different, only odd harmonics can appear ; n can be 1, 3, 5, 7...
- Distance between adjacent antinodes: ½λ

Doppler Effect (Toward)

When the source/observer are moving towards each other, the:
1) Observed wavelength gets smaller
2) Observed frequency gets bigger
3) Observed period gets smaller

Doppler Effect (Away)

When the source/observer are moving away from each other, the:
1) Observed wavelength gets bigger
2) Observed frequency gets smaller
3) Observed period gets bigger

fbeat

beat frequency: happens when two different, but similar, frequencies interfere: fbeat = f₂ - f₁