A photon of wavelength 100mm acts as a mass of? My text book gives the answer 2.21×10^-41. but a photon can't have mass because when an object travels with speed of light it's mass becomes infinite.
Here's what your textbook did:
And you're right about a photon being maseless, this is an incorrect application of
Check this link out for more info on what the formula can be used for:
"a photon can't have mass because when an object travels with speed of light it's mass becomes infinite"
None of that makes any sense
- A photon is said to have zero rest-mass, as in, in its own reference frame it is massless.
So how do you reason that it can gain infinite mass? You are grossing up from zero!