A river 100 m wide flows due south at 1 m/s. A boat that travels 1 m/s relative to the water is pointed due east as it crosses from the west bank. The boat reaches the east bank
A)due east of its starting point.
B)100 m farther south.
C)141 m farther south.
D)none of the above

Question

Quizplus · Accepted Answer

The boat will reach 100 m farther south because while it moves eastward across the river, the southward flow of the river also carries it south at 1 m/s. Since it takes 100 seconds to cross (100 m / 1 m/s), it will also have moved 100 m south.

A River 100 M Wide Flows Due South at 1