Determine Mass of Penny: Millikan Experiment

[braeden]

First post on this forum so hoping it is in the right place. In class today we did an experiment where our teach took two paper cups, and placed X amount of pennies in one before stacking the other cup inside of it. We had 10 of these cup/penny contraptions each and a scale. The purpose of this experiment was to determine how much a penny weighted. What I did was first massed them all. I then though that if I subtract the smallest mass from all the larger ones I know the difference MUST be from an increase in amount of pennies. From this though I am not quite sure where to go, should I assume the smallest increase between two different masses is the mass of a penny? My teacher compared it Millikan's Oil Drop experiment not really sure what he did to calculate the charge on an electron and how it can be applied though.

 

[Mentz114]

You can safely assume that the smallest difference you can find is an integer multiple of the penny weight. What Millikan did is measure the force that appeared when an oil drop was ionised by losing or gaining some electrons ( pennys ). This might be of use http://en.wikipedia.org/wiki/Oil_drop_experiment