Chapter 9, Problem 119P

In Fig. 9-83, block 1 slides along an x axis on a frictionless floor with a speed of 0.75 m/s. When it reaches stationary block 2, the two blocks undergo an elastic collision. The following table gives the mass and length of the (uniform) blocks and also the locations of their centers at time t = 0. Where is the center of mass of the two-block system located (a) at t = 0, (b) when the two blocks first touch, and (c) at t = 4.0 s?

Figure 9-83 Problem 119

Block	Mass (kg)	Length (cm)	Center at t = 0
1	0.25	5.0	x = −1.50 m
2	0.50	6.0	x = 0