8.15 - To warm up for a match, a tennis player hits the \( 57.0-\mathrm{g} \) ball vertically with her racket. If the ball is stationary just
8.24 Block \( A \) in Fig. E8.24 has mass \( 1.00 \mathrm{~kg} \), and block \( B \) has mass \( 3.00 \mathrm{~kg} \). The blocks are forced together, compressing a spring
270 CHAPTER 8 Momentum, Impulse, and Collisions
\( S \) between them; then the system is released from rest on a level, frictionless surface. The spring, which has negligible mass, is not fastened to either block and drops to the surface after it has expanded. Block \( B \) acquires a speed of \( 1.20 \mathrm{~m} / \mathrm{s} \). (a) What is the final speed of block \( A \) ? (b) How much potential energy was stored in the compressed spring?
which was initially at rest, travels at \( 45.0^{\circ} \) to the original direction of \( A \) (Fig. E8.31). (a) Find the speed of each asteroid after the collision. (b) What fraction of the original kinetic energy of
Figure E8.31