Question

16.
A boat moves with a speed of 5 km/h relative to
the water in the river flowing with speed of 3 km/h
and having a width of 1 km. The time taken by the
boat to cross the river by shortest path will be
(1) 30 min
(2) 15 min
(3) 45 min
(4) 20 min​

Answer 1

Answer:

15 min

Explanation:

velocity of river=3

velocity of boat=5

width=1

formula:

time=w÷$\sqrt{square of velocity of boat - square of velocity of river}$