OpenStax College Physics, Chapter 29, Problem 22 (Problems & Exercises)

This is College Physics Answers with Shaun Dychko. We are going to calculate the frequency of a photon from a gamma ray that has an energy of 1.00 megaelectron volt; the prefix 'mega' means multiply by 10 to the 6 so this is 1.00 times 10 to the 6 electron volts. and our equation for the energy of a photon is Planck's constant times frequency so we can divide both sides by Planck's constant to solve for frequency so frequency is the energy divided by Planck's constant. So that's 1.00 times 10 to the 6 electron volts divided by 4.14 times 10 to the minus 15 electron volt seconds and I have chosen this particular version of Planck's constant since the units are convenient, we end up with the electron volts canceling and we have reciprocal seconds here we have 1 over seconds is our unit and 1 over seconds is abbreviated with the units hertz, which is the unit for frequency. So this is 2.42 times 10 to the 20 hertz.