Consider an electromagnetic wave impinging on an electron. It is easy to show kinematically that the average value of the time rate-of-change of the electron€™s momentum vector p is proportional to the average value of the time rate-of-change of the work, W, done on it by the wave. In particular,

Accordingly, if this momentum change is imparted to some completely absorbing material, show that the pressure is given by Eq. (3.51).

Transcribed Image Text:

1 / dW ()-:("); dt dt (S(t))T (P(t))r (3.51)