Hello, I was recently given the task to find experimentally the moment inertia of a sphere. I thought of rolling the sphere down an inclined plane and applying conservation of energy to the sphere. The equations i came up with are: mgh = 1/2mv(adsbygoogle = window.adsbygoogle || []).push({}); ^{2}+ 1/2Iω^{2}solving for v^2 we come up with the equation:

v^{2}= (2mgR^{2}h)/(mR^{2}+ I) now if we plot v^{2}(h) we come up with a straight line through the origin and (2mgR^2)/(mR^2+ I)should be its slope. solving for I we come up with I = mR^{2}/k(2g-k) where k is the gradient. Now if we equate this with 2/5 mR^{2}which is the mathematical formula for the moment inertia of the sphere we should come up with the same result, but the mass and radius cancel. This makes no sense. Please help :(

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Experimental determination of the moment inertia of a sphere

Have something to add?

Draft saved
Draft deleted

**Physics Forums | Science Articles, Homework Help, Discussion**