Question

The number of photons of electromagnetic radiation with a frequency 5.0 MHz that have a total energy of 3.0 J is .

Answer 1

we have:

frequency = 5.0 MHz = 5.0*10^6 s-1

1st calculate energy of 1 photon

we have:

frequency = 5.0*10^6 s-1

we have below equation to be used:

Energy = Planck constant*frequency

=(6.626*10^-34 J.s)*(5.0*10^6) s-1

= 3.313*10^-27 J

number of photon = total energy/energy of 1 photon

n = 3.0/3.313*10^-27

= 9.06*10^26

Answer: 9.06*10^26