SOLUTION: a stretch of a river 300m wide has a straight parallel banks and the speed of the current is 4m/s .A man starts to cross the river in a boat from point A on one bank. The boat can

Question 798635: a stretch of a river 300m wide has a straight parallel banks and the speed of the current is 4m/s .A man starts to cross the river in a boat from point A on one bank. The boat can sail at 5m/s in calm water. if he takes a course making an angle of 60 degrees upstream with the banks. Find the distance where he lands from the point directly opposite A.
Answer by Finavon(81) (Show Source): You can put this solution on YOUR website!
A: width of river 300m
Tan = O/A
Target distance (O) upstream from point opposite (as if no current)
O= Tan 30 x 300
O=0.577 x 300=173.2m (upstream)
Cos=A/H
Distance travelled (H) = 300/cos30 = 300/0.866 = 346.4m
Current will carry 4/5 of this distance = 277.1m (downstream)
Final landing -173.2+277.1 = 103.9m downstream
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