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

Transverse wave picture

- sine waves with the shape of a sine curve

B. Parts of a transverse wave1. 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 wave4. 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 waves1. No crests or troughs2. 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 wavesD. 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