A 6-m-long, 490 kg steel beam extends horizontally from the point where it has been bolted to the framework of a new building under construction. A 75 kg construction worker stands at the far end of the beam. What is the net torque on the beam

Amachinist turns the power on to a grinding wheel, at rest, at time t = 0 s. the wheel accelerates uniformly for 10 s and reaches the operating angular velocity of 96 rad/s. the wheel is run at that angular velocity for 40 s and then power is shut off. the wheel slows down uniformly at 1.5 rad/s2 until the wheel stops. in this situation, the time interval of deceleration is closest to: