Waves

Waves transport energy from one place to another. They are temporary displacement in either matter or fields. There are two types of wave, those like sound which are called __________ and the more common __________.

Types of waves

In __________ waves the displacement is at right angles with the direction that the wave is travelling. While in __________ waves the displacement is along the direction that the wave is travelling.

The maximum displacement is known as the __________ of a wave and is measured from the __________, this is where the matter (or field) would be if there wasn't a disturbance.

measurements of a wave

We can also measure the __________, this is simply the distance between two identical parts of the wave. For ease we normally measure peak to peak or trough to trough.

There are two related time measurements we can make. The __________ is the amount of time to complete one cycle (wave) and __________ is the number of cycles (waves) in a bit of time. One cycle per second is one hertz.

A high frequency sound wave has a high __________ and a sound wave with a large amplitude sounds __________.

If a wave has a wavelength, λ and a frequency, f, then the wave speed, c, can be calculated by:

Wave Equation Magic triangle

c = λ f

where:
c = Wave speed in __________, __________
λ = Wavelength in __________, __________
f = Frequency in __________, __________

Complete the table below (to 1 s.f.):

Wave Frequency Wavelength Speed
Yellow light 0.51 x 10 15 Hz 590 x 10 -9 m           
X - rays            0.1 x 10 -9 m           
Microwave 6 x 10 9 Hz                      
Radio waves from space            0.8 m           

Wave speeds are generally fixed by the medium the wave is travelling through. All electromagnetic waves (light) travel at the same speed in a __________. So as their wavelength increases their frequency decreases in a 'see-saw' relationship.