A 32.0 kg wheel, essentially a thin hoop with r=1.20 m is rotating at 280 rev/min. It must be brought to stop in 15.0 s. How much work must be done to stop it?
The Attempt at a Solution
W=(1/2)I[tex]\omega[/tex]f^2 - (1/2)I[tex]\omega[/tex]i^2
Rev in 15 sec = 70 rev => 140[tex]\Pi[/tex] radians in 15 sec.
I'm not sure which equation(s) to use. I've tried plugging numbers into all of them and getting stuck or wrong answers. Thanks!!