1. A 0.27 kg volleyball, with an initial velocity of 2.7 m/s horizontally, hits a net, stops, and then drops to the ground. The average force exerted on the volleyball by the net is 33 N[W]. How long is the ball in contact with the net? 2. A hammer has a mass of 2.0kg and is moving horizontally at a speed of 6.0 m/s when it strikes a nail, driving it 2 cm farther into a piece of wood. a. What was the kinetic energy of the hammer? b. What is the average force exerted on the nail by the hammer? 3. What is the speed of an electron in an accelerator, if its mass is 9.1x10-31 kg and its kinetic energy is 9.2x10-18J? 4. How fast is a 1200 kg car travelling if it has 480 kJ of kinetic energy? If the energy doubles how fast is the car now travelling? 5. A 45 g golf ball leaves the tee with a speed of 43 m/s after a golf club strikes it. Determine the magnitude of the average force applied by the club to the ball, assuming that the force is parallel to the motion of the ball and acts over a distance of 2.0 cm. 6. A 68.5 kg skier rides a 2.56 km chair lift from the base of the mountain to the top. The lift is at an angle of 13.9o to the horizontal. a) Determine the skier's gravitational potential energy at the top of the mountain relative to the base of the mountain. b) How fast will the skier be travelling when they reach the bottom of the mountain