Question

9. The width of river is 1km, the velocity of boat is 5km/h. The boat covered the width of river in shortest time 15min.
Then the velocity of river stream is​

Answer 1

Answer:

t=

u

2

−v

2

d

4

1

=

(5)

2

−v

2

1

16

1

=

25−v

2

1

v = 3 km/hr.