A river flows due east at 3 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) 120 m
B) 50 m
C) 45 m
D) 60 m
E) 70 m

Question

A river flows due east at 3 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?
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A) 120 m
B) 50 m
C) 45 m
D) 60 m
E) ​70 m

Quizplus · Accepted Answer

We can use the formula:

distance = rate × time

First, we need to find the time it takes for the boat to cross the river. We can use the fact that the distance across the river is 300 meters and the boat's velocity relative to the water is 15 m/s:

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

Now we can use the boat's velocity and the time it took to cross the river to find how far downstream the boat moved:

distance downstream = velocity downstream × time
velocity downstream = 3 m/s (since the river flows due east)
time = 20 s
distance downstream = 3 m/s × 20 s
distance downstream = 60 m

Therefore, the boat moved 60 meters downstream by the time it reached the far shore. The correct answer is D) 60 m.

A River Flows Due East at 3 M/s