Estimate the change in gravitational potential energy when a person with mass 80 kg rise from bed to a standing position. Assuming that the center of mass of a person is elevated by approximately Δh=0.50m.

diagram is missing, but i will try to explain your doubt.

answer:

amplitude is the maximum displacement or distance moved on a point of a vibrating body or wave measured from its equilibrium position.it is equal to half the length of vibration path.

waves moving from a fast medium to a slow medium will experience a reflection as light travels more slowly than red light. total internal reflection occurs when the critical angle is.