this lab is very similar to mine(adsbygoogle = window.adsbygoogle || []).push({});

basically i can only seem to derive a portion of the formula, I=mgb/al - mb^2

where b- radius, g-gravity, al- angular acceleration.

I do not get the right answer:

here is what i did do however,

Fnet=ma

T-mg=-ma (acceleration is downwards)

so T=(mg-ma)

so then

Tnet=I*al (where al is angular acceleration not acceleration)

so then

T*b=I*al

(b*mg-b*ma)/al = I

as u can see this is not the correct solution..but is a start

the solution i need to get to is

I=mgb/al - mb^2

can someone help me out - thanks :)

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# Homework Help: Help Deriving formula for moment of inertia lab

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