1) A 0.250-kg ball is moving straight up at a speed of 12.7 m/s. At this time its height is y = 110. m. What are the ball's (a) kinetic energy, (b) gravitational potential energy, and (c) total mechanical energy at this time?

2) (a) A bus is stopped at a red light. When the light turns green the bus accelerates to 11.5 m/s in the positive x direction in 4.50 s. What is the acceleration of the bus during this time? (b) When a car pulls in front of the bus, the bus slows to 7.5 m/s in 1.15 s. What is the acceleration of the bus during this time? (c) If the bus stays at 7.5 m/s for the next 4.73 s, how far does it travel during this time?

3) (a) A box of mass 8.32 kg is sliding to a stop over a distance of 3.65 m. What are the forces acting on it? (b) If the kinetic friction force on the box has a magnitude of 2.50 N, what is the work done by it? (c) What was the box's initial speed?