Q1. Three identical train cars, coupled together, are rolling east at 1.2 m/s. A fourth car travelling east at 4.4 m/s catches up with the three and couples to make a four-car train. A moment later, the train cars hit a fifth car that was at rest on the tracks, and it couples to make a five-car train. What is the speed of five-car train?
Q2. A man pushes a lawn mower on a level lawn with a force of 186 N. If 35 percent of this force is directed downward, how much work is completed by the man in pushing the mower 6.5 m?