A river is flowing at a speed of 5, km/h in a | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(B) Let the speed of the man in still water be $u = 20\, km/h$ and the speed of the river flow be $v = 5\, km/h$.When swimming along the direction of

Vedclass · Accepted Answer

$3\, h\, 12\, min$

Vedclass · Answer

(B) Let the speed of the man in still water be $u = 20\, km/h$ and the speed of the river flow be $v = 5\, km/h$.When swimming along the direction of the flow (downstream),the effective speed is $u + v = 20 + 5 = 25\, km/h$.The time taken to travel from $A$ to $B$ is $t_1 = \frac{Distance}{Speed} = \frac{30}{25} = 1.2\, hours$.When swimming against the direction of the flow (upstream),the effective speed is $u - v = 20 - 5 = 15\, km/h$.The time taken to travel from $B$ back to $A$ is $t_2 = \frac{30}{15} = 2\, hours$.The total time taken is $T = t_1 + t_2 = 1.2 + 2 = 3.2\, hours$.Converting $0.2\, hours$ to minutes: $0.2 	imes 60 = 12\, minutes$.Thus,the total time is $3\, h\, 12\, min$.

Similar Questions

$A$ person can row with the stream at $8 \text{ km/h}$ and against the stream at $4 \text{ km/h}$. The speed of the current is (in $\text{km/h}$):

$A$ boat travels $60$ km downstream and $20$ km upstream in $4$ hours. The same boat travels $40$ km downstream and $40$ km upstream in $6$ hours. What is the speed (in $km/hr$) of the stream?

$A$ man can row $7 \frac{1}{2} \, km/hr$ in still water. If in a river running at $1.5 \, km/hr$,it takes him $50 \, minutes$ to row to a place and back,how far off is the place? (in $km$)

$A$ boat moves downstream at the rate of $1 \, km$ in $10 \, minutes$ and upstream at the rate of $4 \, km/h$. What is the velocity of the current (in $km/h$)?

If a man's rate with the current is $12 \text{ km/h}$ and the rate of the current is $1 \frac{1}{2} \text{ km/h}$,then his rate against the current is ...... $\text{km/h}$.

Vedclass Test Series

Exam Paper Generator

Online Exam Module