A fisherman sets out upstream on a river. His small boat,powered by an outboard motor, travels at a constant speed v instill water. The water flows at a lower constant speed vw. Thefisherman has traveled upstream for 2.37 km when his ice chestfalls out of the boat. He notices that the chest is missing onlyafter he has gone upstream for another 17.6 minutes. At that point,he turns around and heads back downstream, all the time travelingat the same speed relative to the water. He catches up with thefloating ice chest just as he returns to his starting point. Howfast is the river flowing? Solve this problem in two ways.
(a) First, use the Earth as a reference frame. With respect to theEarth, the boat travels upstream at speed v - vw and downstream atv + vw.
___ km/h
(b) A second much simpler and more elegant solution is obtained byusing the water as the reference frame. This approach has importantapplications in many more complicated problems, such as calculatingthe motion of rockets and satellites and analyzing the scatteringof subatomic particles from massive targets.
___ km/h
A fisherman sets out upstream on a river. His small boat,powered by an outboard motor, travels at a constant speed v instill water. The water flows at a lower constant speed vw. Thefisherman has traveled upstream for 2.37 km when his ice chestfalls out of the boat. He notices that the chest is missing onlyafter he has gone upstream for another 17.6 minutes. At that point,he turns around and heads back downstream, all the time travelingat the same speed relative to the water. He catches up with thefloating ice chest just as he returns to his starting point. Howfast is the river flowing? Solve this problem in two ways.
(a) First, use the Earth as a reference frame. With respect to theEarth, the boat travels upstream at speed v - vw and downstream atv + vw.
___ km/h
(b) A second much simpler and more elegant solution is obtained byusing the water as the reference frame. This approach has importantapplications in many more complicated problems, such as calculatingthe motion of rockets and satellites and analyzing the scatteringof subatomic particles from massive targets.
___ km/h
