Q17. Average force exerted on a non-reflecting surface at normal incidence is $2.4 \times 10 ^ { - 4 } \mathrm {~N}$. If $360 \mathrm {~W} / \mathrm { cm } ^ { 2 }$ is the light energy flux during span of 1 hour 30 minutes, Then the area of the surface is:\\
(1) $0.2 \mathrm {~m} ^ { 2 }$\\
(2) $20 \mathrm {~m} ^ { 2 }$\\
(3) $0.1 \mathrm {~m} ^ { 2 }$\\
(4) $0.02 \mathrm {~m} ^ { 2 }$