Answer:
The energy of a gamma ray can be calculated using the formula:
E = hc/λ
where h is Planck's constant (6.626 x 10^-34 J s), c is the speed of light (2.998 x 10^8 m/s), and λ is the wavelength of the gamma ray.
Substituting the given values, we get:
E = (6.626 x 10^-34 J s) x (2.998 x 10^8 m/s) / (4 x 10^-14 m)
Simplifying this expression, we get:
E = 4.969 x 10^-13 J
Therefore, the energy of the gamma ray is 4.969 x 10^-13 joules.