Lab Quiz 6

why we use I=mg/(alpha fric+alpha) instead of the given formular I=mr(g-ra)/(afr+a)??

I'm almost positive my calculations are correct, but Maple keeps saying it's wrong, here are my numbers and calculations:
mass = .2 kg
radius = 2.5 cm = .025 m
% = 1.25
a = 0.268
a_f = -0.177

so

(1.25/100)*.025 = 0.0003125

(.2*9.81)/(|-.177|+.268)
1.962/.445
= 4.4089888

4.4089888*0.0003125
= 0.001377809

Okay I know those calculations are correct but for some reason Maple TA did not like it. I took it again and it worked.

this is the exact thing i did and got it right.

I = mr(g-(radius*a)) /(|afric|+a) .... the absolute sign in the denominator is a must dont forget it and dont forget to convert the radius to meters.

then simply divide your % for radius by 100.

then multiply that by what youu got for I.