A boat covers the distance between two points downstram in 12 hrs and the same distance downward with its engine off 36 hrs. Then it covers the same distance upstream in
Answers
Answer:
It takes 12h to reach the distant with the velocity of the boat and the velocity of the stream. When the engines are off, its only the velocity of the stream takes the boat to the distant in 36h.
distant (d)
V=D/T
velocity of the stream (Vs)
velocity of the boat (Vb)
The boat travels a distance (d) downstream in 12h
Vs + Vb =d/12 ---------(i)
(both velocities are in the same direction)
When the engines are off there is only the velocity of the stream.
Vs = d/36
substitute in (i)
d/36 + Vb = d/12 => Vb = d/18
If the boat travel a same distance upstream
Vb - Vs (because the velocities are in different directions)
i.e d/18 - d/36 = d/36
so that it will take 36h to travel the same distant upstream with the engines on.
Answer:
Answer is 36 hrs
Explanation:
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