Chapter 13: General Wave Properties

Wave motion

Mean of transferring energy without transfer of matter

Wavefront

imaginary line joining crests (or troughs)

Ray

Direction of wave travel

Wavelength

Distance between 2 adjacent crests (or troughs)

Mean position

Where the particles would lie if they were at rest

Amplitude

Maximum displacement from mean position

Frequency

Number of oscillations on a point per unit time

1/t

Time period

time for one oscillation/ one cycle

1/f

Speed

distance covered per unit time

v= f * wavelength

Graph displacement against distance

1 cycle= wavelength

Graph displacement against time

1 cycle= time period

Refraction

deep —> less deep = towards normal

less deep —> deep = away from normal

Transverse Waves

Direction of vibrations perpendicular to energy flow

Example: electromagnetic waves

Has Crests and Troughs

Longitudinal Waves

Direction of vibrations parallel to energy flow

Example: sound and ultrasound waves

Has Compressions and Rarefactions

Compression

High particle density

Higher air pressure

Rarefactions

Low particle density

Lower air pressure