(a)[2]
State the meaning of a photon.
(b(i))[3]
Calculate the wavelength of this light.
(b(ii))[1]
The beam emitted by the laser has a power of $1.0 \times 10^{-2}\,\text{W}$. Calculate the number of photons emitted per unit time by the laser.
(b(iii))[4]
The photons strike a surface normally. Half of the photons are absorbed by the surface, and the other half are reflected. Determine the average force exerted on the surface by the beam of photons.