Question -
Answer -
Wavelength of the monochromatic light, λ =632.8 nm = 632.8 × 10−9 m
Power emitted by the laser, P =9.42 mW = 9.42 × 10−3 W
Planck’s constant, h =6.626 × 10−34 Js
Speed of light, c = 3 × 108 m/s
Mass of a hydrogen atom, m =1.66 × 10−27 kg
(a)The energy of each photonis given as:
The momentum of eachphoton is given as:
(b)Number of photons arrivingper second, at a target irradiated by the beam = n
Assume that the beam has auniform cross-section that is less than the target area.
Hence, the equation forpower can be written as:
(c)Momentumof the hydrogen atom is the same as the momentum of the photon,
Momentum is given as:
Where,
v = Speed of the hydrogen atom
