# National Aeronautics and Space Administration

## Student Worksheet: EM Spectrum - A Calculation Investigation

You are given the following two equations that express the relationships between the speed, the wavelength, the energy and the frequency of light:
c = l n
speed = wavelength x frequency

E = hn
energy = Planck's constant x frequency

1. Check the equations above and show that the units match on each side of the equations.

2. Manipulate both equations to solve for energy (E) as a function of wavelength (l) and fundamental constants. Show each step. Show that the units match on each side of the resulting equations.

3. Given a photon's wavelength, frequency or energy in the chart below, use the above equations to solve for the other two (in the units indicated). Use the useful constants page if you need to. Use the chart of the electromagnetic spectrum (below the table) to fill in the part of the electromagnetic radiation range for each row.

 Wavelength (m) Frequency (Hz) Energy (J) ElectromagneticRadiation Range 0.001 7.0 x 1013 5.0 x 10-7 2.0 x 10-15 1.2 x 1022

### Thought Questions

In three minutes, summarize what you have learned about light and the relationship between its energy, frequency and wavelength. Write an unanswered question you still have.

 A service of the High Energy Astrophysics Science Archive Research Center (HEASARC), Dr. Alan Smale (Director), within the Astrophysics Science Division (ASD) at NASA/GSFC