Suppose that the swimmer in the figure below has a swimming speed relative to the water of 0.45 m/s, while the speed of the current is 2.0 m/s. If it takes the swimmer 160 s to cross the river, how wide is the river?
As long as the swimmer is perpendicular to the river, the speed of the current doesn't really matter. The distance will always remain constant.
D = speed * time
D = 0.45 * 160
D = 72m
To find the width of the river, you can use the formula:
Width of the river = Swimmer's speed relative to the water * Time taken to cross the river
Given:
Swimmer's speed relative to the water = 0.45 m/s
Time taken to cross the river = 160 s
Using the formula, we can calculate the width of the river as follows:
Width of the river = 0.45 m/s * 160 s
Width of the river = 72 meters
Therefore, the width of the river is 72 meters.