What is the energy and momentum of a photon having frequency $v$?

An electron with rest mass $m_{0}$ moves with a speed of $0.8 c$. Its mass when it moves with this speed is

When an $X$-ray photon collides with a proton,its frequency:

The photon energy in units of $eV$ for an electromagnetic wave of wavelength $2 \, cm$ is

$A$ bulb has a power of $60 \, mW$ and emits light of wavelength $6000 \, \mathring{A}$. Calculate the number of photons emitted by the bulb per second.

$A$ proton moving with a momentum $p_{1}$ has a kinetic energy $1/8$th of its rest mass-energy. Another light photon having energy equal to the kinetic energy of the proton possesses a momentum $p_{2}$. Then,the ratio $\frac{p_{1}-p_{2}}{p_{1}}$ is equal to