This simulation shows a wave on a string approaching from the left to the end of the string. The wave will be reflected at the end of the string, with a phase shift dependent on whether the end of the string is fixed or free to move in the vertical direction. Look carefully at the disturbance that is eventually built up. In due course, you will have equal amplitude waves travelling in the two directions. What is the resultant disturbance?
Pressing Run will start the simulation. You may pause the simulation or step your way through it, if you find the free running one too fast to follow. Credits