I was given a small steel ball and asked to find its density.(adsbygoogle = window.adsbygoogle || []).push({});

To do this we weighed the ball and measured its diameter.

Its weight was found to be 16.1 grams (.0161Kg) with the scales having an accuracy of +- .1g (.0001Kg)

To measure the diameter we had to use a ruler. It was decided that the balls diameter was 1.45cm (.0145m)

We were then asked to estimate the error in our measurement of the diameter. We decided this would be .0005m

From that we found the radius to be .0073m +- .0003m

Now, knowing that P(density) = M(mass)/V(volume) and that V = (4/3)(Pi)(r^3) we could find P

P = .0161/((4/3)(Pi)(.0073^3)) = 9880 Kg/m^3

If our measurments were reasonably correct is that a right answer? We were told it should be between 6000-8000Kg/m^3

now, the next part required us to find the uncertenty in the density. the uncertenty of the mass was .0001kg, but how could i find the uncertenty of V given the uncertenty of R is .0003?

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# Homework Help: Experimental Uncertenties

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