Assume they weigh the same: If Sally is pushed harder than Bill, Bill would come back sooner, Bill has a greater amplitude. Assume Bill is heavier than Sally: If both are pushed equally hard, Bill would come back sooner, Sally has a greater amplitude
Explanation:
The amplitude of a wave refers to the maximum amount of displacement of a particle on the medium from its rest position. In a sense, the amplitude is the distance from rest to crest. Similarly, the amplitude can be measured from the rest position to the trough position.
In simpler terms, amplitude stands for the maximum extent of a vibration or oscillation, measured from the position of equilibrium. Amplitude is proportional to the energy of a wave, a high energy wave having a high amplitude and a low energy wave having a low amplitude.