If you want to cross a river in a motorboat in the least amount of time (least time in water), you should head
A) the time will be independent of how you head your boat
B) slightly downstream.
C) directly downstream.
D) slightly upstream.
E) straight across the river.

Question

Quizplus · Accepted Answer

To cross a river in the least amount of time, you should aim the motorboat straight across the river. This minimizes the distance traveled over water, directly opposing the river's current, and thus takes the least amount of time. Heading in any other direction would result in a longer path due to the river's current affecting the boat's trajectory.

If You Want to Cross a River in a Motorboat