A boat which has a speed 5 km/h in still water crosses a river 100 m along the shortest possible path in 1.5 min. The velocity of river water in km/h is :

A boat which has a speed 5 km/h in still water crosses a river 100 m a

1.	A boat which has a speed 5 km/h in still water crosses a river 100 m along the shortest possible path in 1.5 min. The velocity of river water in km/h is :
Answer» 1 3 4 4.1 Solution :SINCE man crosses along SHORTEST path `vec(OB)` represent tesultant velocity of man w.r.t. RIVER `\|vec(V_(R))\|=(OB)/t=0.1/(1.5/60)=60/15`=4km/h `vec(OA)` repesents velocity of man `:. AB=SQRT(OA^(2)-OB^(2))=sqrt(25-16)=3` `:.` Velocity of river =3km/h

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A boat which has a speed 5 km/h in still water crosses a river 100 m along the shortest possible path in 1.5 min. The velocity of river water in km/h is :

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