The velocity of a photon is proportional to (where $\nu$ is frequency):

The radiant energy from the Sun incident on the Earth's surface is $2 \ cal/cm^2 \cdot min$. If the average wavelength of solar radiation is $5500 \ \mathring A$,then the number of photons incident per minute on a surface area of $1 \ cm^2$ on the Earth's surface is ............ $(h = 6.6 \times 10^{-34} \ J \cdot s, 1 \ cal = 4.2 \ J)$

If $5\%$ of the energy supplied to a bulb is irradiated as visible light,how many quanta are emitted per second by a $100 \, W$ lamp? Assume the wavelength of visible light is $5.6 \times 10^{-5} \, cm$.

The wavelength of an electron and a photon are equal. If the energy of the photon is $E$ and the momentum of the electron is $p$,what is the value of $p/E$?

$A$ 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

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