Question

The width of the river is 1 km and velocity of river water is 5 km/hr. There are two boats at the same point on the bank. The velocity of each boat in still water is 10 km/hr. One of the boat starts its journey along the bank, it travels a distance 1 km upstream, and return back. Simultaneously, another boat starts its journey to the other bank by shortest path and returns back. Which of the boat returns to the starting point first?

Answer 1

Answer:

answer is journey to the

Answer 2

Width of the river=1km
Velocity of river water= 5km/h
Velocity of both boats with respect to river= 10 km/h
Let A be the first boat
Boat A in upstream
V= 10-5 =5 km/h. Width (d) =1km
t1 = d/v =1/5h =12 min

Boat A in downstream
Ú = 10+5= 15 km/h
d=1 km
t2= 1/15 =4 min
TA= t1 +t2= 16 min

Let B be the boat to travel along the shortest path and return
Total distance D = 2 km
Velocity of boat along the shortest path= 5✓3 km/h
TB= D/Vb=2/5✓3 =14 min
TB<TA boat B return to it's Starting point first