1. An experimental 1800-kg car travels at a constant speed of 25 m/s around a circular test track that is 90 m across. What is the kinetic energy of the car? A) zero joules B) 3.6 * 105 J C) 2.3 * 104 J D) 5.6 * 105 J E) 7.2 x 105 J 2. The kinetic energy of a car is 7 * 106 J as it travels along a horizontal road. How much work is required to stop the car in 10 s? A) zero joules B) 7 * 104 J C) 7 * 105 J D) 7 x 106 J E) 7 * 10' J 3. The kinetic energy of a 2500-kg truck is 17.2 x 105 J. What is the speed of the truck? A) 688 m/s B) 33 m/s C) 28 m/s D) 37 m/s E) 1.45 m/'s 4. In which one of the following systems is there a decrease in gravitational potential energy? A) a boy jumps down from a bed B) a girl stretches a horizontal spring C) a crate rests at the bottom of an inclined plane D) a car ascends a steep hill E) water is forced upward through a pipe 5. During the construction of a high rise building, a 400-kg block is vertically lifted 25 meters from the surface of the earth. What is the change in the gravitational potential energy of the block? A) 16 J B) 98100 J C) 8000 J D) 125000 J E) zero joules