Question

A man is crossing a river of width 100 m on a motorboat. The velocity of the motor boat is 4 m/s eastward and the velocity of the water current is 3 m/s northward. What is the resultant velocity of the boat and how much time will it take for the man to reach the other shore of the river?

Answer 1

The resultant velocity of the boat = 5 m/s

The time it will take for the man to reach the other shore of the river = 25 s

Step-by-step explanation:

width of river = 100 m

The velocity of the motorboat = 4 m/s eastward

The velocity of the water current = 3 m/s northward

The resultant velocity of the boat is:

R^2 = 4^2 + 3^2

= √ (4^2) + (3^2)

= √16 + 9

=√25

= 5 m/s

The time it will take for the man to reach the other shore of the river is:

d = 100 m

v = 4 m/s

t = d / v

t = 100 / 4

t = 25 s