Chapter 10 Section 2: Glencoe Pages 294-299 Wave Properties Chapter 10 Section 2: Glencoe Pages 294-299

I. Wave properties A. Transverse waves look like a sine curve (looks like an “S” on its side) - example drawing – all parts labeled

I. Wave properties - sine waves with the shape of a sine curve Transverse wave picture - sine waves with the shape of a sine curve

B. Parts of a transverse wave 1. Crest – highest point on a transverse wave 2. Trough – lowest point on a transverse wave 3. Amplitude – greatest distance a particle is displaced from its normal resting position

B. Parts of a transverse wave 4. Wavelength – distance between 2 successive identical points on a wave  symbol =  (lambda) measured in meters

Wave Properties 5. Period (T) – time required for one full wavelength to pass a certain point (measured in seconds) 6. Frequency (f)– number of wavelengths that pass a point in 1 second  measured in hertz (Hz)  named after Heinrich Hertz (1888)  1 Hz = 1 wavelength (vibration) per second  can hear 20 Hz (low)  20,000 Hz (high)

C. Longitudinal waves 1. No crests or troughs 2. Compressions and rarefactions (stretched) - example drawing of longitudinal wave (click on picture)

C. Longitudinal waves Compressions – areas where the medium is squeezed together closer than at equilibrium Rarefactions – areas where the medium is stretched or expanded farther apart than at equilibrium One wavelength is from compression to compression or rarefaction to rarefaction

Electromagnetic waves D. Electromagnetic waves (drawn as transverse) Electromagnetic spectrum and uses Radio waves – radio broadcasts, radar Microwaves – cell phones, microwave ovens Infrared waves – remote controls, CD-ROMS Visible light – vision Ultraviolet waves – tanning beds, kills bacteria X-rays – images of internal organs and bones Gamma rays – radiation therapy

II. Wave speed A. Wave speed – speed at which a wave travels through a medium Speed = wavelength / period =  / T or v =  f