waves

Describing Waves:

Waves - a series of vibrations caused by an energy input

A wave does not transfer matter. It only transfers information and energy.

Types of Waves:

• Transverse Waves e.g. light waves

• Longitudinal Waves e.g. sound waves

Transverse Waves -

Transverse waves oscillate/vibrate perpendicular to the direction of energy transfer (e.g. water waves). Particles only vibrate up and down, they don’t move with the wave. It is only energy that travels from one point to another.

• Electromagnetic Waves

• Water Waves

• Earthquake S Waves

Longitudinal Waves -

Longitudinal waves oscillate/vibrate parallel to the direction of energy transfer (e.g. sound waves). Particles only vibrate side to side, they don’t move with the wave. It is only energy that travels from one point to another. Sections of a longitudinal wave that are pushed together are called compressions and that are stretched out are called rarefractions.

• Sound Waves

• Slinky

• Earthquake P Waves

Wavelength - the distance between two matching point on neighbouring waves, measured in metres

Amplitude - the maximum distance a point moves from its rest position

Period - the time for one complete cycle of the wave, measured in seconds

Frequency - the number of complete waves that pass a point every second, measured in hertz

Velocity - the speed at which the energy of the wave travels from one place to another, measured in m/s

Equilibrium - the horizontal line that is in the middle of the wave

Crest / Peak - the highest point a wave goes

Trough - the lowest point a wave goes

Wave Speeds:

Wave Speed = Frequency x Wavelength

Refraction:

Refraction - when a ray of light changes speed and direction

Fast

Away from the normal

Slow

Towards the normal