Exploring the Concept of Photon Momentum in Physics | Homework Help

[logearav]

Homework Statement

Photon don't have mass. But they possesses momentum.

Homework Equations

The Attempt at a Solution

Momentum is product of mass and velocity. Then how photons which don't have mass can have momentum?

 

[gneill]

Momentum is a product of mass and velocity only for things that have rest mass. For things without rest mass (like photons) another expression holds.
$$p = \frac{h \nu}{c} = \frac{h}{\lambda}$$

 

[logearav]

Thanks gneill for your clarification

 

[ehild]

The momentum of the photon can be written also as p=mc, where m=E/c². (And E=hν)

ehild

 

[rwisz]

This is a common question that arises when exploring the concept of photon momentum in physics. The answer lies in the fact that photons, being particles of light, have energy and momentum that are related to their frequency and wavelength. This is described by the famous equation E=hf, where E is the energy of the photon, h is Planck's constant, and f is the frequency of the photon. This equation shows that photons have energy, and since momentum is also a product of energy and velocity, photons also have momentum. In fact, the momentum of a photon is given by the equation p=hf/c, where c is the speed of light. This means that the momentum of a photon is directly proportional to its frequency, and inversely proportional to the speed of light. Therefore, although photons do not have mass, they do possess momentum and can transfer this momentum to other particles through interactions, such as in the process of absorption or emission of light. This concept of photon momentum is crucial in understanding various phenomena in physics, such as the photoelectric effect and the behavior of light in different mediums. So, while photons may not have mass, they still play a significant role in the laws of momentum and energy in the world of physics.