Enter your Name:   Enter your E-mail Address:  Be sure to write all your answers with the proper number of significant figures and to list the units that go with your answers! 01. Distinguish between work and energy. What do they have in common? What are their differences? 02. Define kinetic and potential energy. 03. In a typical electrical power plant, a fuel (like coal) is burned to boil water. The steam from that water is used to turn large fans which operate the electrical generator. The turning of the fans causes the generator to make electricity, which moves down the wires. Starting with the fuel, describe each of the energy transformations that take place. Tell what form (chemical, electrical, etc.) and type (potential or kinetic) of energy is transformed in each stage of this process. 04. A man tries to pull an object as pictured below. How could he change the way he is pulling in order to increase the work that he can perform? 05. Is it ever possible for the work done by friction to increase the kinetic energy of an object? 06. A roller coaster is designed so that the car is pulled up to the top of the first hill by a chain and pulley system. After that, however, the car coasts the rest of the way through the track, never being pulled or pushed again until its brakes stop it. With these conditions, what is wrong with the roller coaster designed below? 07. Two workers must pick up bricks that lie on the ground and place them on a worktable. They each pick up the same number of bricks and put them on the same height worktables. The first gets the job done in one-half the time that the second takes. Did one of the workers do more work than the other? If so, which one? Did one of the workers exert more power than the other? If so, which one? 08. When friction takes energy from an object, where does the energy go? 09. A refrigerator repairman pushes a refrigerator 75 cm to get access to the panel behind it. If the worker did 175 Joules of work, what force did he exert? 10. A toy car (m = 25 grams) on a track starts from rest at the top of a 2.3 meter hill and rolls down. The car then goes up a ramp and flies off the track (see diagram below). If the end of the ramp is 0.91 meters high, at what speed does the car leave the track? 11. A bicyclist travels up a 14.1-m hill and reaches the top with a speed of 9.7 m/sec. At that point, the bicyclist stops pedaling and coasts down the hill and up the next one. If the next hill is 2.3 meters high, how fast will the bicyclist be traveling when it reaches the top of the second hill? The combined mass of the bicycle and the cyclist is 89 kg. 12. An angry carpenter kicks a 2.3-kg block of wood across the floor with an initial velocity of 5.1 m/sec. If the coefficient of kinetic friction between the wood and the floor is 0.67, how far will it travel before coming to rest? 13. A 345-gram ball rolls down a 3.1-m hill. If it started from rest and gets to the bottom with a speed of 4.2 m/sec, how much work did friction perform? 14. A 101 Watt light bulb burns for 30.0 minutes. How much energy was consumed? 15. A machine must move an object 15.1 meters by exerting a 121 Newton force. If the machine must get the job done in 2.3 minutes, how much power must the machine's motor provide?