Chapter 27, Problem 50A

To determine

To Calculate: Momentum of photon by using equation $p=mv$

Explanation of Solution

Introduction:

Light is composed of photons which do not have any rest mass. So, one cannot find the momentum of a photon using the equation $p=mv$ , which requires mass for the calculation of the momentum.

The momentum of a photon can be calculated using the de Broglie wavelength equation:

  $p=\frac{h}{\lambda }$

Where, h is the Planck’s constant and $\lambda$ is the wavelength.

Conclusion:

One cannot use $p=mv$ to find the momentum of a photon.