Waves transfer energy but not matter. Waves may be transverse (eg water wave) or longitudinal (eg sound wave). Wave motion can be described using the terms amplitude, wavelength, frequency and period.
A ripple tank can be used to measure the wavelength of waves on the water's surface. A ripple tank is a transparent shallow tray of water with a light shining down through it onto a white card below to more easily see the motion of the ripples created on the water's surface. Ripples can be made by hand but to generate regular ripples it is better to use a motor.
A simple tray of water can be used to measure the speed of waves travelling in water. One end of the tray is lifted and dropped gently to produce the waves.
Method 1: To measure the wavelength of waves in a ripple tank.
Method 2: To measure the speed of waves in a tray of water.
Depth of water in cm | Length of 10 waves in cm | Wavelength in cm |
---|---|---|
... | ... | ... |
Depth of tray (cm) | Length of tray (cm) | Trial 1 | Trial 2 | Trial 3 | Trial 4 | Trial 5 | Mean | Mean (cm/s) |
---|---|---|---|---|---|---|---|---|
... | ... | ... | ... | ... | ... | ... | ... | ... |
Hazard | Consequence | Control measures |
---|---|---|
Electrical components near water | Shock, damage to components | Secure electrical components before adding water taking care not to splash |
Wet floors are slippery | If water splashes on floor during the experiment people may slip and be injured | Do not overfill the trays, place them down |