There is one long bungee cord strung out between two corners or walls in your lab room - make sure it is weighted down at one end and fastened securely at the other end. the tension in the string is just the weight of the large mass hanger and masses weighting it down. practice plucking the cord on one end, so that you generate a pulse that travels to the other end and then back again. this will happen several times, until the amplitude (height of wave) will die down calculate and predict the speed of the wave pulse, using your knowledge of parameters affect wave speed. there is sample bungee cord length near the front of the room in case you need to make measurements without taking down the long bungee cord.