Problem 7 Relative (a) You are driving on the freeway and notice your speedometer says co. The car in front of you appears to be coming towards you at speed up, and the car behind you appears to be gaining on you at the same speed up. What speed would someone standing on the ground say each car is moving? (b) Suppose a certain type of fish always swim the same speed. You watch the fish swim a certain part of a river with length L. You notice that it takes a time ,to for the fish to swim downstream but only to to swim upstream. How fast is current of the river moving? (c) You now want to swim straight across the same river. If you swim (in still water) with a speed of " what direction should you swim in? (d) How long does it take to get across if the river has a width of LL