# The radiation force due to source of power P on a perfectly reflecting surface will be

Q: The radiation force due to source of power P on a perfectly reflecting surface will be

(a) P/3c

(b) 2P/c

(c) P/2c

(d) P/c

Solution :(b)

E = m0c2

or , m0c = E/c

Change in momentum Δp = 2m0c = 2E/c

F = dp/dt = 2p/c (As dE/dt =p)