Question

A stone is thrown into a pond. What happens to the amplitude of the resulting waves as they get farther from the point where the stone hit the water? Explain.

An athlete of average size is hanging from the end of a 20 m long rope, which has a mass of 4 kg and is attached to a hook in the ceiling of a gym. If the athlete makes a sudden movement at the end of the rope, estimate how long it will take the disturbance to reach the hook.

Answer 1

When a stone is thrown into a pond, the energy distribution in water takes place in the form of circular waves. The wave's amplitude decreases when the waves get farther from the point because the radius of the circular wave increases and the energy has to distribute through that larger circumference, and there are other factors like viscosity, damping (due to air resistance). Non-conservative forces make the amplitude decrease.