Wavelength of Microwaves -

This assignment requires a microwave oven, a microwave-safe casserole dish, a bag of marshmallows, and a ruler. (The oven must be of the type that has no mechanical motion-no turntable or rotating mirror. If there is a turntable, remove it first.)

First, open the marshmallows and place them in the casserole dish, completely covering it with a layer one marshmallow thick. Next, put the dish of marshmallows in the microwave and cook on low heat. Microwaves do not cook evenly and the marshmallows will begin to melt at the hottest spots in the microwave. Heat the marshmallows until they begin to melt in four or five different spots. Remove the dish from the microwave and observe the melted spots. Take the ruler and measure the distance between the melted spots. You will find that one distance repeats over and over. This distance will correspond to half the wavelength of the microwave. Finally, do some research and determine the frequency of the microwaves used in your oven. (NOTE: It is NOT 60Hz; that is the frequency of the electricity that comes from the wall outlet.)

With all this information, calculate an experimental value of the speed of "light" (actually, in this case, the speed of the microwaves, which are, like light, simply electromagnetic radiation).

1. Compare your experimental value to the known value of c=299792458ms.

2. List 4 or 5 reasons why your value is not the same as the known value. For each reason, briefly explain

 (a) Why it affected your experimental value

 (b) Whether it caused your value to be too low, or too high.