Revise: Wave and Sound
Describing wave motion, transverse and longitudinal waves, wave characteristics and graphs, wave behaviour at boundaries, and sound waves.
A wave transports energy, not matter.
A cork bobs in place as a water wave passes.
Transverse: perpendicular oscillation. Longitudinal: parallel oscillation.
Light/water = transverse; sound = longitudinal.
Displacement-distance graph shows wavelength; displacement-time graph shows period.
Peaks 4m apart β Ξ» = 4m.
Particles oscillate about a fixed position as the wave passes through.
A stadium wave: fans move in place, the wave travels around.
Only transverse waves can be polarized.
Polarized sunglasses block glare (light is transverse).
Don't confuse the two graph types β they look similar but mean different things.
Time between peaks (time graph) = period.
Diffraction is strongest when the gap is comparable to the wavelength.
AM radio diffracts around hills better than FM.
Sound needs a medium β it cannot travel through a vacuum.
Sound travels faster through solids than air.
Don't forget to divide by 2 β the echo time covers a round trip.
1500m/s, 0.8s echo β sea floor 600m deep.