A radiation of energy E falls normally on a perfectly reflecting surface. The momentum transferred to the surface is (c = velocity of light)

A radiation of energy E falss normally on a perfectly reflecting surface. The momentum transferred to the surface is

A radiation of energy E falls normally on a perfctly refelecting surface . The momentum transferred to the surface is

A radiation of energy E false normally on a perfectly reflecting surface. What is the momentum transferred to the surface is k£/c.what is the value of k ?