| A | B |
|---|
| A pinball bangs against a bumper, giving the ball a speed of 42 cm/s. If the ball has a mass of 50.0 g, what is the ball's kinetic energy in joules? | 4.41 x 10^-3 J |
| A spoon is raised 21.0 cm above a table. If the spoon and its contents have a mass of 30.0 g, what is the gravitational potential energy associated with the spoon at that height relative to the surface of the table? | 0.062 J |
| The staples inside a stapler are kept in place by a spring with a relaxed length of 0.115 m. If the spring constant is 51.0 N/m, how much elastic potential energy is stored in the spring when its length is 0.150 m? | 0.031 J |
| What is the kinetic energy of an automobile with a mass of 1250 kg traveling at a speed of 11 m/s? | 75,625 J |
| A mechanic pushes a 2.50 x 10^3-kg car from rest to a speed of v, doing 5000 J of work in the process. During this time, the car moves 25.0 m. Neglecting friction between car and road, find v and the horizontal force exerted on the car. | 2 m/s; 200 N |
| A person's heart and head are 1.3 m and 1.8 m above the feet, respectively. Determine the potential energy associated with 0.50 kg of blood in the heart relative to (a) the head and (b) the feet. | -2.45 J; 6.38 J |
| An archer pulls her bowstring back 0.400 m by exerting a force that increases uniformly from zero to 230 N. What is the equivalent spring constant of the bow? How much work does the archer do in pulling the bow? | 575 N/m; 46 J |
| What is the speed of a 0.145 kg baseball if its kinetic energy is 109 J? | 38.77 m/s |
| A car has a kinetic energy of 4.32 x 10^5 J when traveling at a speed of 23 m/s. What is its mass? | 1633.27 kg |
| A 1.50 x 10^3 kg car accelerates uniformly from rest to 10.0 m/s in 3.00 s. What is the work done on the car in this time interval? | 75,000 J |
