Question

You are a member of a production crew filming a nature explorer in the Rocky Mountains. The explorer needs to swim across a river to his campsite. By watching debris flowing down the river, you estimate that the stream is flowing at 0.669 m / s. In still water, he can swim at 0.735 m / s. At what angle, less than 90 degree, with respect to the shoreline would you advise him to swim to travel directly across the stream to his campfire? water is near freezing in temperature. Typically a human can only swim in such water for about 300 seconds (or 5 minutes) before hypothermia sets in. Calculate the time the explorer spends in the water if the river is 27.5 meters wide. Based on your results, what would be your advice to the explorer?

Answer 1

From the figure the angle is o- sin 10.669 θ = Sin 0.735) 65.53 Hence angle with respect to shore is ' 90-65.53 0' = 24.470 Shore Explorer 0.735 0.669I Compsite The speed require swim straight across the stream is v =V(0.735m/s )2-(0.669m9) 0.304 m/s Hence time require to cross the river is 27.5 m 0.304 m/s t 90.46s Approved. He1l get cold but he should be able to make it across