1. Use the concepts of momentum, impulse, potential and kinetic energy to solve to following problems. Read each carefully, draw pictures and label everything. Show all your work. 1. A 1600 g car travels at a speed of 12.5 m/s. What is its kinetic energy? 2. Joseph has a mass of 45 kg and a speed of 10.0 m/s. (a) What is Joseph’s kinetic energy? (b) Joseph’s speed decreases to 5.0 m/s. Now what is his kinetic energy? 3. Miranda lifts a 180 kg barbell to a height of 1.95 m. What is the increase of PE of the barbell? 4. Dakota raised a 12.0 N book from a table 75 cm above the floor to a shelf 2.15m above the floor. Find the change in the system’s potential energy. 5. A professional tennis player serves a ball with 150 N of force. The .060 kg ball is in contact with the racket strings for .030 s. If the ball starts at rest, what is its kinetic energy as it leaves the racket? 6. A 2.00 x 10^3 kg car has a speed of 12.0 m/s when it hits a tree. The tree doesn’t move, and the car comes to rest. Find the change in kinetic energy of the car. 7. You throw a clay ball at a hockey puck on ice. The smashed clay ball and the hockey puck stick together and move freely. Is momentum conserved in the collision? Explain. 8. An archer fits a .30 kg arrow to the bowstring. He exerts an average force of 201 N to draw the string back .5 m. If the energy goes into the arrow, with what speed does the arrow leave the bow?