Light is incident normally on a completely absorbing surface with an energy flux of $25 \mathrm {~W} \mathrm {~cm} ^ { - 2 }$. If the surface has an area of $25 \mathrm {~cm} ^ { 2 }$, the momentum transferred to the surface in 40 min time duration will be:\\
(1) $6.3 \times 10 ^ { - 4 } \mathrm {~N} \mathrm {~s}$\\
(2) $5.0 \times 10 ^ { - 3 } \mathrm {~N} \mathrm {~s}$\\
(3) $3.5 \times 10 ^ { - 6 } \mathrm {~N} \mathrm {~s}$\\
(4) $1.4 \times 10 ^ { - 6 } \mathrm {~N} \mathrm {~s}$