A boat which has a speed of 5 km h^(-1) in still water crosses a river of width 1 km along the shortest possible path in 15 minutes. The velocity of…

Question

A boat which has a speed of 5 km h^(-1) in still water crosses a river of width 1 km along the shortest possible path in 15 minutes. The velocity of the river water in km h^(-1) is

MARKS Content Team · Accepted Answer

Correct answer: (B) 3 km h^(-1). Vertical displacement = 1 km t=15/60=1/4 h ∴ V_bcosθ=( 1 )/((14))=4 km h^(−1) ⇒cosθ=4/V_b =4/5 ⇒sinθ=3/5 By velocity triangle ABC, sinθ=V_r/V_b ∴ V_rV_b=3/5 ⇒V_r5=3/5 ⇒V_r=3 km h^(−1)

A boat which has a speed of $5 km h^{- 1}$ in still water crosses a river of width $1 km$ along the shortest possible path in $15$ minutes. The velocity of the river water in $km h^{- 1}$ is

Solution

More Motion In Two Dimensions Questions

A boat which has a speed of 5 km h-1 in still water crosses a river of width 1 km along the shortest possible path in 15 minutes. The velocity of the river water in km h-1 is

Solution

More Motion In Two Dimensions Questions

A boat which has a speed of $5 km h^{- 1}$ in still water crosses a river of width $1 km$ along the shortest possible path in $15$ minutes. The velocity of the river water in $km h^{- 1}$ is