FORCE EXERTED BY A LIGHT BEAM ON A SURFACE

There is a parallel beam of light of larger aperture . Let I be the intensity of light . Perfectly reflecting sphere of radius r is kept in the path of this parallel beam . Find the force exerted by the light beam on sphere .

A narrow beam of monochromatic light of wavelength lamda emitted from a source of power P is propogating in the positive x-direction. After being reflected from a perfectly reflecting plane mirror of area vector vecA=A(-hati-hatj) , the beam falls on a metal plate of surface area A[ vecA is along outward normal at mirror]. the force exerted by light beam on the mirror is vecF and Deltavecp is change in momentum of each photon then [cis speed of light in vacuum]

A parallel beam of monochromatic light of wavelength 500nm is incident normally on a perfectly absorbing surface. The power through any cross- section of the beam is 10 W. Find (a) the number of photons absorbed per second by the surface and (b) the force exerted by the light beam on the surface.

A parellel beam of monochromatic light of wavelength 500 nm is incident normally on a perfectly absorbing surface. The power through any cross section of the beam is 10 W. Find (a) the number of photons absorbed per second by the surface and (b) the force exerted by the light beam on the surface.

A parellel beam of monochromatic light of wavelength 500 nm is incident normally on a perfectly absorbing surface. The power through any cross section of the beam is 10 W. Find (a) the number of photons absorbed per second by the surface and (b) the force exerted by the light beam on the surface.

A parallel beam of monochromatic light of wavelength 500nm is incident normally on a perfectly absorbing surface. The power through any cross- section of the beam is 10 W. Find (a) the number of photons absorbed per second by the surface and (b) the force exerted by the light beam on the surface.

A parallel beam of monochromatic light of frequency v is incident on a surface. Intensity of the beam is I and area of the surface is A. Find the force exerted by the light beam on the surface for following cases– (i) the surface is perfectly absorbing and the light beam is incident normally on it. (ii) the surface is perfectly reflecting and the light beam is incident normally. (iii) the surface is perfectly absorbing and the light beam is incident at an angle of incidence theta . (iv) the surface is perfectly reflecting and the light beam is incident at an angle of incidence theta .