What is the speed of a photon with respect to another photon if (a) the two photons are going in the same direction and (b) they are going in opposite directions?

Two photons having

Two photons having

What is the wavelength of a photon of energy 1 eV?

What is the energy of photon whose wavelength is 6840 Å ?

Point A and B are 90 km apart from each other on a highway. A car starts from A and another from B at the same time. If they go in the same direction they meet in 9 hours and if they go in opposite directions they meet in 9/7 hours. Find their speeds.

Two trains take 3s to pass another when going in the opposite directions but only 2.5s if the speed of one is increased by 50% . The time one would take to pass the other when going in the same direction at their original speed is

What will be the energy of a photon which corresponds to the wavelength of 0.50 Å?

Two photons of same frequencies moving in same medium have

In an experiment on photoelectric effect, a photon is incident on an electron from one direction and the photoelectron is emitted almost in the opposite direction. Does this violate conservation of momentum ?

What is the energy ( in eV) of a photon of walelength 12400A ?