Also tried this:
Net torque = I * α
I = (.5 * 3.2kg * .185m2) = .0548 kg*m2
α = ((350rpm / 60 s) - 0) * 2π / 2.4s = 15.27 rad/s
Net torque = .0548 * 15.27 = .8363 Nm
Net torque = F * radius
.8363 = F * .185
F = 4.52 N
This one seems more correct but I've done it wrong so many times I don't...
Homework Statement
The 3.2kg , 37-cm-diameter disk in the figure is spinning at 350 rpm .
How much friction force must the brake apply to the rim to bring the disk to a halt in 2.4s?
Homework Equations
F = m * a
I = (1/2) * mass * radius2 (I probably need to use this but I can't figure...