Question

If the energy and momentum of a photon are E and p respectively, then the velocity of photon will be

• A. $\frac{E}{p}$
• B. ${\left(\frac{E}{p}\right)}^2$
• C. Ep
• D. $3\times {10}^{8}m/s$

Answer 1

Answer: (A), (D)

$\frac{E}{p}$
$3\times {10}^{8}m/s$

Energy of a photon moving with velocity c is given by:
$E=m{c}^2$
and momentum of the photon is
$P=mc$
So, the velocity of photon will be:
$v=E/P=c=3\times {10}^{8}m/s$

So, the answers are options (A) & (D).