Key learning points

1. As a water wave moves forward, each bit of water is moving up and down (oscillating), not forward.
2. Water waves are transverse waves: the direction of oscillation is 90° to the direction of energy transfer.
3. The amplitude of a water wave is the greatest distance water moves above and below the rest position.
4. Waves that pass through each other can ‘add up’ or ‘cancel out’; this is called wave superposition.
5. Water waves reflect from hard barriers, obeying the laws of reflection.

Keywords

• Oscillation - back–and–forth movement

• Transverse - describes a wave where the direction of oscillation is 90° to the direction of energy transfer

• Amplitude - the greatest distance a material moves from the rest position when a wave passes through that material

• Wave superposition - the process of waves ‘adding up’ or ‘cancelling out’ as they pass through each other

• Wavefront - lines drawn to represent the positions of the peaks of a wave

Common misconception