Question

A swimmer crosses a river 300 yards wide by swimming at a constant velocity of 1 mile/hour perpendicular (that is, at right angles to) to the riverbank. The river is flowing at 3 miles per hour. What is the velocity (expressed in m/s) of the swimmer relative to an observer sitting on the shore? How far downstream will the swimmer’s landing point be from the starting point (expressed in m)? Note: Convert all variables to the metric (mks) system before performing your calculations.

Answer 1

add the two velocities in a right triangle. √(1^2+3^2) = √10 mi/hr

300 yds = 300/1760 = 0.17 miles
so, it will take 0.17 hours to cross the river. Since the river flows 3 times as fast as he swims, he will wind up 3*0.17 = 0.51 miles downstream.

Answer 2

Thank you! Do you think you can help me another problem? All I know is the formula but dont know how to plug in the numbers in it. If you dont mind.