Light with an energy flux of `40W//cm^(2)` falls on a non-reflecting surface at normal incidence. If the surface has an area of `20cm^(2)`, find the average force exerted on the surface during a `30min` time span.

Light with an energy flux of 18 W//cm^(2) falls on a nonreflecting surface at normal incidence. If the surface has an area of 20 cm^(2) , find the average force exerted on the surface during a 30 minute time span.

Light with an energy flux of 18 W//cm^(2) falls on a nonreflecting surface at normal incidence. If the surface has an area of 20 cm^(2) , find the average force exerted on the surface during a 30 minute time span.

Light with an energy flux of 18W//cm^(2) falls on a non-reflecting surface at normal incidence. If the surface has an area of 20cm^(2) , find the average force exerted on the surface during a 30 minute time span.

Light with an energy flux of 18 W//cm^(2) falls on a non-reflacting surface at normal incidence. If the surface has an area of 20 cm^(2) , find the average force exerted on the surface during a 30 minute time span.