- #1

Krushnaraj Pandya

Gold Member

- 697

- 73

## Homework Statement

A perfectly reflecting solid hemisphere of radius R is placed in the path of a parallel beam of light of large aperture, if the beam carries an intensity I, what is the force exerted by the beam on the hemisphere?

## Homework Equations

radiation pressure=I(1+ro)(cos^2(x))/c

I is intensity, po is reflection coefficient, x is angle of incidence and c is speed of light.

## The Attempt at a Solution

ro=1 here, Intuitively the force will be less than on a disc of the same radius, so it is less than 2*pi*r*r*I/c, I also know integration will be involved but I can't figure out how to go about it. I'd appreciate some help, thank you