E = mc2/sqrt(1 - v2/c2) is simply the energy of a given unit of matter with mass m and velocity v, right?
2007-01-03 10:50:27 · 3 answers · asked by ツ 1 in Science & Mathematics ➔ Physics
A Photon has not rest mass i.e. it doesn't exist if it's not moving.
when it's moving it has momentum given by plank's const h divided by the wavelength of the light.
2007-01-03 10:59:20 · answer #1 · answered by thirstybadger 1 · 0⤊ 0⤋
The mass of a photon is hf/(c^2) where h is Planck's constant ( 6.67E-34 joule-secs), f is the frequency of the photon in hertz and c is the speed of light, 3E8 metres/sec. So a blue photon has about twice the mass of a red photon because it's more energetic.
2007-01-03 19:02:12 · answer #2 · answered by zee_prime 6 · 0⤊ 0⤋
A photon has no mass but it does have momentum.
2007-01-03 18:52:53 · answer #3 · answered by tentofield 7 · 0⤊ 0⤋