The sun delivers 10^3 W/m2 of electromagnetic flux to the earth’s surface . The total power that is incident on a roof of dimensions 8 m × 20 m, will be

Q: The sun delivers 103 W/m2 of electromagnetic flux to the earth’s surface . The total power that is incident on a roof of dimensions 8 m × 20 m, will be

(a) 2.56 × 104 W

(b) 6.4 × 105 W

(c) 4.0 × 105 W

(d) 1.6 × 105 W

Sol: Total Power = Solar constant x area

= 103 × (8 × 20)

= 1.6 × 105 W

Radiation Force on the roof is ,

$\large F = \frac{Total \; Power}{Velocity \; of \; Light} $

$\large F = \frac{1.6 \times 10^5}{3 \times 10^8} $

= 5.33 × 10-4 N