Question

Bobo, the clown, can swim at 2.0 m/s. he must make a landing directly across to the north side of the styx river, which is 100. m wide. the river flows at 6.0 m/s due east at this point. bobo’s biggest problem is that he can only swim while facing due north. how can he possibly make a landing at the desired location?

Answer 1

We are given the following:

Bobo's swimming speed = 2.0 m/s
Width of the river = 100 m
Flowrate of the river = 6.0 m/s due east

First, we need to illustrate the problem. Draw the river with a width of 100 meters. Then, the flow of the river, east at 6 meters per second. Lastly, draw Bobo at one side of the river facing north and an arrow representing swimming speed at 2 meters per second.

Now, we can use the Pythagorean theorem to solve this rate problem.

c^2 = a^2 + b^2 

c = speed of Bobo needed
a = speed of Bobo facing north
b = flow rate of the river going east

c^2 = 2^2 + 6^2 

c = 6.32 m / s should be his speed to overcome the current and make a landing at the desired location.