A plane electromagnetic wave of wave intensity 6 W / m 2 strikes a small mirror area 40 cm 2, held perpendicular to the approaching wave. The momentum transferred by the wave to the mirror each second will be

Question

A plane electromagnetic wave of wave intensity 6 W / m 2 strikes a small mirror area 40 cm 2, held perpendicular to the approaching wave. The momentum transferred by the wave to the mirror each second will be (A) 6.4 × 10-7 kg - m / s 2 (B) 4.8 × 10-8 kg - m / s 2 (C) 3.2 × 10-9 kg - m / s 2 (D) 1.6 × 10-10 kg - m / s 2

Tardigrade Admin · Accepted Answer

Momentum transferred in one second P=(2 U/c)=(2 Sa v A/c) =(2 × 6 × 40 × 10-4/3 × 108) =1.6 × 10-10 kg - m / s 2

Q. A plane electromagnetic wave of wave intensity $6 W / m^{2}$ strikes a small mirror area $40 c m^{2}$ , held perpendicular to the approaching wave. The momentum transferred by the wave to the mirror each second will be

$6.4 \times 1 0^{- 7} k g - m / s^{2}$

$4.8 \times 1 0^{- 8} k g - m / s^{2}$

$3.2 \times 1 0^{- 9} k g - m / s^{2}$

$1.6 \times 1 0^{- 10} k g - m / s^{2}$

Momentum transferred in one second
$P = \frac{2 U}{c} = \frac{2 S _{a v} A}{c}$
$= \frac{2 \times 6 \times 40 \times 1 0 ^{- 4}}{3 \times 1 0 ^{8}}$
$= 1.6 \times 1 0^{- 10} k g - m / s^{2}$

Q. A plane electromagnetic wave of wave intensity 6W/m2 strikes a small mirror area 40cm2, held perpendicular to the approaching wave. The momentum transferred by the wave to the mirror each second will be

6.4×10−7kg−m/s2

4.8×10−8kg−m/s2

3.2×10−9kg−m/s2

1.6×10−10kg−m/s2