Wavelength, Speed of Light, Frequency - IWB

Two activities for practice and revision of speed of light, wavelength and frequency. This can be used as a homework (worksheet) and then students enter their results on to the same file opened on the IWB, they can mark each others work or their own. This has proved to be very motivating. I suggest that you change the .xls extension to .xlt before use. As an xlt it can be placed on a VLE as a self marking exercise for revision or differentiation by task. Please rate and comment if useful.