# Finding the mass of a penny

1. Nov 9, 2006

### dcgirl16

i was given 26 envelopes each with a different number of pennies inthem. I weighed each envelope and the mass of the empty one. THen i subtracted the mass of the enveleope and put the mass in order from least to greatest. Using this information i need to find the mass of one penny, even tho i dont have the number of pennies in the envlopes. THis lab is supposed to represent milikans experiment. THe only thing i have figured out is that if you take the first mass and multiply it by 1.013 you get the next mass and then you multiply that and get the next one. Except i dont know how to usethis info what else can i do.

2. Nov 9, 2006

### OlderDan

Once your masses of envelope contents are arranged in order, you can arrange those numbers on a rectangular grid (a graph) with the mass on one axis and the position of the mass on the second axis with the positions chosen so that the data points form a straight line that goes through the origin. The positions should be positve integer multiples of one grid distance. When the line has been formed, you should be able to deduce the change in mass for an increase of one penny.