2.5 Momentum of electromagnetic waves

1.1 Displacement current
1.3 Maxwell's equations

2.1 Properties of electromagnetic waves
2.2 Production of electromagnetic waves
2.3 Energy density of electromagnetic waves
2.4 Intensity of electromagnetic waves
2.5 Momentum of electromagnetic waves
2.6 Radiation pressure
2.7 Poynting vector
2.8 Electromagnetic spectrum

An electromagnetic wave carries linear momentum.

The electromagnetic wave strikes the surface at normal incidence and transports a total energy $U$ to the surface in a time $t$.

If the surface absorbs all the incident energy, the total momentum $p$ transported to the surface is,

For complete absorption, $$p = \frac{U}{c}$$

If the surface is a perfect reflector and incidence is normal then the momentum transported to the surface is,

For complete reflection, $$p = \frac{U}{c}$$