For my A level coursework I have to come up with and carry out an experiment. I have chosen to investigate the speed of waves in liquids. I plan to use a ripple tank, set to create waves of a certain frequency, which I will vary. I will measure the wavelength and use the equation v = fλ to find the speed. I found an equation on this page , which looked to be of use: v = √(gd) where g is acceleration due to gravity and d is the depth of the liquid. I will use this equation to verify the speed. In the next stage of my investigation, I planned to relate the speed of the waves to the viscosity of the liquid they are in. Intuitivly, I feel there should be a relationship between the two, however, I have not been able to find one online or in textbooks. Also, the fact that v = √(gd) suggests that it doesn't matter what the liquid is, the speed will always be the same for any liquid of the same depth. Could someone please advise if there is a relationship, or if wave speed is independant of the liquid. Thanks in advance.