2007-10-20 14:20:23 · 5 answers · asked by blueridgemotors 6 in Science & Mathematics ➔ Physics
E=mc^2. This refers to a system in its center of mass frame. What is it about equals that you don't understand?
Photons have energy but no *rest* mass. That means you cannot bring them to a rest. They still have relativistic (inertial) mass. For example, if you put a photon of energy E in a box lined with perfect mirrors, the box's mass would increase by E/c^2.
2007-10-20 14:24:52 · answer #1 · answered by Dr. R 7 · 3⤊ 0⤋
Light. Light has energy but no mass.
2007-10-20 21:40:35 · answer #2 · answered by Dennis H 4 · 1⤊ 1⤋
Light. One photon has E=hf, meaning that its energy is equal to a constant (h) times its frequency. There is no mass involved.
2007-10-20 21:23:55 · answer #3 · answered by Anonymous · 1⤊ 1⤋
Light?
2007-10-20 21:23:09 · answer #4 · answered by Anonymous · 1⤊ 1⤋
light energy
2007-10-20 21:22:53 · answer #5 · answered by DesmondH815 2 · 1⤊ 1⤋