ripple tank

• aim - describe how to use a ripple tank to measure the wavelength, frequency and speed of water waves
• a ripple tank is used to observe the features of water waves . its a shallow tray of water , in the water is a vibrating bar . the bar is connected to a power pack
• 1 - when the bar vibrates, it creates waves on the surface of the water
• 2 - above the tank is a lamp and below the tank is a sheet of white paper. when light shines through the water, it produces an image of the waves on the paper
• 3 - record waves using a mobile phone to play back recording at different speeds and freeze the image
• 4 - to measure wavelength, place a ruler on the paper and freeze image of waves. then measure the distance of one wave and ten waves further (measure 10 wavelengths)
• 5 - to find one wavelength, divide the total of 10 wavelengths by 10
• 6 - to find frequency , place a timer next to paper and count the number of waves passing a point in 10 seconds. then divide by 10 to find one wave. measure this in Hz
• 7 - to find speed, use wave equation frequency (Hz) x wavelength (m) = speed (m/s)