BITSAT2021PhysicsDual Nature of MatterActual
A plane electromagnetic wave is incident on a plane surface of area A, normally and is perfectly reflected. If energy E strikes the surface in time t then force exerted on the surface is ( c= speed of light)
Options
- A2 E Atc
- BE 2 c
- C2 E ct
- Dzero
Correct answer
C. 2 E ct
Step-by-step solution
Incident momentum, p= E c For perfectly reflecting surface with normal incidence p=2 p= 2 E c ; F = p t = 2 E c t