1. A 4.1kg box slides a distance of 11.5m. If the coefficient of kinetic friction is 0.15, what is the work done by the friction force? 2. During a workout, the football players at Rutgers State University ran up the stadium stairs at a steady pace in 40 s. The stairs are 90 m long and inclined at an angle of 25. If a typical player has a mass of 118 kg, estimate the average power output on the way up. Ignore friction and air resistance.(g = 9.8 m/sz) watts 3. You raise a bucket of water from the bottom of a deep well. If your power output is 101 W, and the mass of the bucket and the water in it is 3.50 kg, with what speed can you raise the bucket? Ignore the weight of the rope. m/s 4. The 2.0 kg block in the figure slides down a frictionless curved ramp, starting from rest at a height ofh = 2.00 m. The block then slides d = 7.40 m on a rough horizontal surface before coming to rest. What is the coefficient of friction between the block and the horizontal surface? 5. A skier traveling 12.0 m/s reaches the foot of a steady upward 18 incline and glides 10.2 m up along this slope before coming to rest. What was the average coefficient of friction? 6. A ZOO-kg roller coaster reaches the top of the steepest hill with a speed of 5.40 km/h. It then descends the hill, which is at an angle of 20 and is 58.0 m long. What will its kinetic energy be when it reaches the bottom? Assume pk = 0.12. J 7. A 20.00-kg child initially at rest slides down a playground slide from a height of 2.70 m above the bottom of the slide. If her speed at the bottom is 2.00 m/s, how much energy is lost due to friction? J 8. A roller coaster reaches the top of the steepest hill with a speed of 5.00 km/h. It then descends the hill, which is at an average angle of 25 and is 40.0 m long. What will its speed be when it reaches the bottom? Assume pk = 0.22. m/s 9. A 0.32kg ball is thrown vertically upward with an initial speed of 13.0 m/s. What is the potential energy of the ball when it has travelled three-quarters of the distance to its maximum height? (Use the launch point to be the zero reference point of measurements of the heights) J is2964 ms2964 ms2 m/s is2964 ms2964 ms296 10. The drawing shows a version of the loop-the-loop trick for a small car. The radius of the loop r = 0.30 m. What is minimum initial speed (v) that the car needs to have in order to remain in contact with the circular track at all times? as29 V 29 6 ms29 964 ms2 6 2964 ms2964 ms2964 $2964 ms2964 ms2