The free body diagram below shows the forces acting on a bicycle as the rider pedals to the right. The vectors are not drawn to scale. The bicycle has aweight of 800 N and a pedaling force of 250 N. As it moves, it encounters 75 N of air resistance. What is the net force on the bicycle in the x-direction?

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: