Light with an energy flux of 9` W cm^(-2)` ? falls on a nonreflecting surface at normal incidence. If the surface has an area of `20 cm^(2)`. The total momentum delivered for complete absorption in one hour is

Options

A. `2.16xx10^(-4)kgms^(-1)`
B. `1.16xx10^(-3)kgms^(-1)`
C. `2.16xx10^(-3)kgms^(-1)`
D. `3.16xx10^(-4)kgms^(-1)`

Answer

C

Explanation

The total momentum delivered is `Deltap=((IA)/(c))t.`
where, I=intensity, A=area of surface, c=speed of light and t=time
`Deltap=((9xx10^(4)xx20xx10^(-4))/(3xx10^(8))xx3600)`
`=2.16xx10^(-3)kgms^(-1)`