Question

a boy starts a point A travels on straight line to a point B at a distance of 3km from A and return to A. If he takes 2 hours to do so his average speed is

Answer 1

Explanation:

Given info : A body starts from a point A, travels to a point B at a distance of 3 km form A returns to A.

=>To find : if he takes two hours to do so, his speed is ...

=>solution : speed of a body is the rate of change of distance covered by the body with respect to time.

=>i.e., speed = total distance covered/total time taken

=>here total distance covered by the boy = distance between A and B + distance B and A = 3 km + 3 km = 6 km

=>total time taken by the boy = 2 hrs

=>now the speed of the boy = 6 km/2 hrs = 3 km/h

:-Therefore the speed of the boy is 3 km/h.

[note : here total displacement of the boy will be zero because initial position and final position of boy are same. so the average velocity of the boy will be zero. ]