Physics - EM Waves Question with Solution | TestHub

$E=\frac{hC}{\lambda }P=\frac{h}{\lambda } \Rightarrow P=\frac{E}{C}$

Initial momentum of light when falls on a perfectly reflecting surface.

$P_i=\frac{E}{C}$

When it is reflected momentum is in opposite direction

$P_f=-\frac{E}{C}$

Net momentum $=P_f-P_i$

$= -\frac{E}{C}-\frac{E}{C}$

$=-\frac{2E}{C}$

$\mathrm{\Delta }P=\frac{2E}{C}$