A river flows due east at 2.0 m/s.A boat crosses the 300-m-wide river by maintaining a constant velocity of 15 m/s due north relative to the water.If no correction is made for the current,how far downstream does the boat move by the time it reaches the far shore?
A)80 m
B)30 m
C)25 m
D)40 m
E)50 m

Question

A river flows due east at 2.0 m/s.A boat crosses the 300-m-wide river by maintaining a constant velocity of 15 m/s due north relative to the water.If no correction is made for the current,how far downstream does the boat move by the time it reaches the far shore?​
A)80 m
B)30 m
C)25 m
D)40 m
E)​50 m

Quizplus · Accepted Answer

We can use the formula:

distance = speed x time

To find the time it takes for the boat to cross the river, we can use:

time = distance / speed
time = 300 m / 15 m/s
time = 20 s

During this time, the river current will have pushed the boat downstream. The distance the boat moves downstream can be found using:

distance = speed x time
distance = 2 m/s x 20 s
distance = 40 m

Therefore, the boat moves 40 meters downstream by the time it reaches the far shore. The correct answer is D) 40 m.

A River Flows Due East at 2