Physics

Problem

A pulse of light of duration 100 ns is absorbed completely by a small object initially at rest. Power of the pulse is 30 mW and the speed of light is

3 \times 10^8

\text{ms}^{-1}

. The final momentum of the object is (a)

0.3 \times 10^{-17}

\text{kg ms}^{-1}

(b)

1.0 \times 10^{-17}

\text{kg ms}^{-1}

(c)

3.0 \times 10^{-17}

\text{kg ms}^{-1}

(d)

9.0 \times 10^{-17}

\text{kg ms}^{-1}