Topic B : Fundamentals of waves

What is a wave

a wave is a means of transferring energy from one point to another without transferring matter between the 2 points

Describe evidence that with water and sound waves it is the wave and not the water or air that travels

Particles in the water move up and down as a wave passes- the particles are not carried to the shore. for sound waves, particles in the material through which the wave is travelling move backwards and forwards as the wave passes

Define and use the term frequency as applied to waves

How many numbers of wave cycles per second (Hz)

determines the pitch, and for light the frequency determines the colour.

Define and use the term wavelength as applied to waves

distance from a point on one wave to a point in the same position on the next wave in metres

Use the terms amplitude, period, wave velocity and wavefront as applied to waves

amplitude= distance from the middle to the top or bottom, in m. The greater the amplitude the louder the sound

period

length of time it takes one wave to pass a given point

wave velocity

speed of the wave in the direction it is traveling, waves travel at different speeds in different materials

wavefront

a surface containing points affected in the same way by a wave at a given time

4.5 Describe the difference between longitudinal and transverse waves by referring to sound, electromagnetic, seismic and water waves- longitudinal waves

longitudinal waves= the oscillations are in line with, or parallel to, the direction of travel of the wave. sound waves are longitudinal as particles in the material through which the wave is travelling move backwards and forwards as the wave passes. seismic waves produce longitudinal waves when solid rock material is pushed and pulled

transverse waves

the oscillations are 90 degrees to the direction of travel or perpendicular. waves on the surface of water are transverse. Particles in the water move up and down as a wave passes. seismic waves can produce solid rock material which move up or down/ side to side. Electromagnetic waves are transverse and do not need a material to travel through

1ST equation for wave speed

wave speed (m/s)= frequency (Hz) x wavelength (m)

v = f ×λ

2nd equation for wave speed

wave speed (m/s)= distance (m) ÷ time (s)

v = x/ t

Describe how to measure the velocity of sound in air

Describe how to measure the velocity of ripples on water surfaces

Calculate depth or distance from time and wave velocity

distance = speed x time

If there is an echo divide distance by 2