8.4. Set Up: Solve: (a) (b) The SUV has twice the mass and therefore twice the momentum and kinetic energy: 8.5. Set Up: Solve: (a) (b) (i) so (ii) so Reflect: K depends on and p depends on so a smaller increase in is required for the lighter ball to have the same kinetic energy. 8.6. Set Up: and Solve: (a) so (b) so (c) (d) 8.7. Set Up: From Problem 8.6, Solve: (a) and so (b) and so Reflect: In (b), and When the mass is increased the speed must be decreased to keep the same kinetic energy. 8.8. Set Up: Consider the system consisting of the two skaters. Assume the heavier skater travels to the right and take this to be the direction. Solve: (a) There is no horizontal external force so The skaters are initially at rest so The lighter skater travels to the left at (b) The kinetic energy of the system was produced by the work the two skaters do on each other. 8.9. Set Up: Consider the person and the earth to be an isolated system. Use coordinates where is upward, in the direction the person jumps. Solve:
This is the end of the preview.
access the rest of the document.