physics
posted by erik .
A 4.0 kg pulley of radius 0.15 m is pivoted about an axis through its center. What constant torque is required for the pulley to reach an angular speed of 25 rad/s after rotating 6.0 revolutions, starting from rest?

Torque=momentinertia*anglular acceleration
Torque= I * angacc
but
wf^2=wi^2+2*angacc*displacement
wf^2=wi^2+2*angacc*revolutions*2PI
where w is in rad/sec, angacc in rad/sec^2
solve for angacc, then torque