The 17-Mg boxcar A is coasting at 1.3 m/s on the horizontal track when it encounters a 10-Mg tank car B coasting at 0.6 m/s toward it as shown in figure. If the cars collide and couple together, determine (a) the speed of both cars just after the coupling, and (b) the average force between them if the coupling takes place in 0.7 s. (c) how many energy losses during this collision and coupling. 1.3 m/s 0.6 m/s A B