<h3>
Answer:</h3>
Total energy is 9.932 × 10^-1 Joules
<h3>
Explanation:</h3>
Using the concept on energy of photons
Energy of a photon, E, is given by;
E = hf, where h is the plank's constant and f is the frequency of the radiation.
But, since frequency is given by dividing the velocity, c, by wavelength, λ,
Then; E = hc/λ
In this case; we are given more than one photons.
Therefore;
Energy = n × hc/λ , where n is the number of photons
Given;
n (the number of photons) = 1.5x10^13 photons
h (plank's constant) = 6.626× 10^-34 J/s
c (speed of light in vacuum) = 2.998 x 10^8 m/s
λ (wavelength of the radiation) = 3.0x10^-12 m
We can calculate energy;
Energy = (nhc)/λ ,
= 9.932 × 10^-1 Joules
Thus the total energy in the 1.5x10^13 photons is 9.932 × 10^-1 Joules