A plane electromagnetic wave of wave intensity 6 W/m2 strikes a small mirror of area 40 cm2, held perpendicular to the approaching wave. The momentum transferred by the wave to the mirror each second will be:
Answer & explanation
Correct answer: option 4
In one second
$P=\frac{2 U}{c}=\frac{2 S_{a v} A}{c}=\frac{2 \times 6 \times 40 \times 10^{-4}}{3 \times 10^8}$
= 1.6 × 10–10 kg–m/s