How does light have energy? How can light exert force?

Question

Here is what I know:

Photons have no mass.

Force is change in momentum over change in time.

Momentum is mass times velocity.

E=mc²

SO HOW DOES LIGHT HAVE ENERGY AAAA

I also read that massless particles can have momentum and I do not understand that at all.

Please explain how all of this is connected and how light has energy and exerts force. Thank you!

In: 9

Answer 1

Photons are unique.

Even though photons have no mass, they still have momentum proportional to their energy, given by the formula p=E/c. Because photons have no mass, all of the momentum of a photon actually comes from its energy and frequency as described by the Planck-Einstein relation E=hf, and NOT E=MC squared.