Question

The speed of boat when moving in the direction perpendicular to the direction of current is 12km/hr.the speed of current is 2km/hr.the speed of boat against current will be

Answer 1

Hey Dear,

◆ Answer -

v' = 9.83 km/s

● Explanation -

Let's consider vb & vc be velocity of boat & river current respectively.

Resultant speed of the boat when its perpendicular to current is given by -

v = √(vb² + vc²)

v² = vb² + vc²

Given that, v = 12 km/h & vc = 2 km/h,

12² = vb² + 2²

vb² = 144 - 4

vb = √140

vb = 2√35

vb = 11.83 km/h

Therefore, speed of the boat against current will be -

v' = vb - vc

v' = 11.83 - 2

v' = 9.83 km/s

Hence, speed of the boat against the river current is 9.83 km/h.

Thanks dear...