Question

A car moving with velocity v1 overtakes a slower car which is moving with velocity v2 at point A .After one hour first car takes a u-turn and travels with velocity v3 and crosses the second car again at B. Distance between A and B is 10 km. Find the velocity v2. If v1 - v2 = v2 + v3

Answer 1

 v2 travels from A to B in 1hr and  distance between A to B is 10 ⇒ v2 is travelling at 10km/hr.

Answer 2

Let us assume that the car A and B meet after a time

′

t

′

Distance travelled by A in that time is vt

=15t

Distance travelled by B is

s=ut+

2

1

at

2

s=

2

3t

2

=15t

t=0,10s

t=0 is trivial . Therefore, at t=10s, both the cars meet.