Two boats start together and race across a 68-km-wide lake and back. Boat A goes across at 68 km/h and returns at 68 km/h. Boat B goes across at 34 km/h, and its crew, realizing how far behind it is getting, returns at 102 km/h. Turnaround times are negligible, and the boat that completes the round trip first wins. a. Which boat wins and by how much?
b. What is the average velocity of the winning boat?

The great sandini is a 60.0-kg circus performer who is shot from a cannon (actually a spring gun). you don’t find many men of his caliber, so you him design a new gun. this new gun has a very large spring with a very small mass and a force constant of 1100 n/m that he will compress with a force of 4400 n. the inside of the gun barrel is coated with teflon, so the average friction force will be only 40.0 n during the 4.00 m he moves in the barrel. at what speed will he emerge from the end of the barrel, 2.50 m above his initial rest position?