- #1
cantgetno
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Homework Statement
You are to design a rotating cylindrical axle to lift 800N buckets of cement from the ground to a rooftop 78.0m above the ground. The buckets will be attached to a hook on the free end of a cable that wraps around the rim of the axle; as the axle turns, the buckets will rise.
What should the diameter of the axle be in order to raise the buckets at a steady 2.00 cm cm/s when it is turning at 7.5rpm?
If instead the axle must give the buckets an upward acceleration of 0.400 m/s^2, what should the angular acceleration of the axle be?
Homework Equations
KE=0.5 I w^2
GPE = mgh or force x height
I=0.5 m r^2 (for a disc/cylinder)
The Attempt at a Solution
GPE=800x78=62400
Then i would have though KE=GPE but as there's no mass for the cylinder that can't be right
thanks in advance