EQUIPMENT
    Fan with four different colored blades
    Strobe
   


NARRATIVE
            The blades of a four blade fan are painted in the following order: blue, red, yellow, and green. The relationship between the strobe frequency and the fan frequency can be obtained by observing the resultant colors. For example, if the strobe frequency is twice the frequency of the fan, the blades will appear to be stationary; that is, two opposite blades will appear green (blue and yellow) and the other two opposite blades appear white (red and green).