Question

A boat travels from south bank to north bank of a river with a maximum speed of "8km/h" .A river current flows from west to east with a speed of "4km/h" .Find the angle with which the boat should be steered to arrive at a point opposite to the pointof

Answer 1

Answer:

30° Towards West from North

Explanation:

Let say Boat moved with an angle α  with East toward North with speed of 8 km /hr

Then Velocity toward East  (west to East) = 8 Cosα

.A river current flows from west to east with a speed of 4km/h

Addition of both speed should be zero so that Boat moves only

with 8Sinα  in North Direction (South to North)

8Cosα + 4 = 0

=> Cosα = - 4/8

=> Cosα = -1/2

=> α = 120 °

120° towards North from East

or 30° Towards West from North