Penny puts Fluffy in one wagon and pushes the wagon, once, as hard as she can. Penny puts Butch in the other wagon and pushes it once, also as hard as she can. Both of the wagons travel across a level surface. Will the motion of the two wagons be different?

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: