1. John's mass is 93.4 kg, and Barbara's is 53.9 kg. He is standing on the x axis at x_J = +9.27 m, while she is standing on the x axis at x_B = +4.16 m. They switch positions. How far and in which direction does their center of mass move as a result of the switch?

2. One object is at rest, and another is moving. The two collide in a one-dimensional, completely inelastic collision. In other words, they stick together after the collision and move off with a common velocity. Momentum is conserved. The speed of the object that is moving initially is 28 m/s. The masses of the two objects are 3.5 and 8.6 kg. Determine the final speed of the two-object system after the collision for the case (a) when the large-mass object is the one moving initially and the case (b) when the small-mass object is the one moving initially.