Question

Two cars are moving in the same direction with a speed of 30 km per hour they are separated from each other by 5km. Third car moving in the opposite direction meets the two car after interval of 4 minutes. What is the speed of the third car.

Answer 1

hello utkarsh... Let the two cars moving in same direction be A and B respectively. A------5km----------B.. now a third car comes from opposite direction .Let it be C. Now relative velocity of C with respect to B will be (vC+30) km/h.. This car C takes 4 min to cover the distance 5 km . Now 4 min=1/15 hour..So ( 30+vC)=5/(1/15)... 30 +vC= 5×15.. vC = 45km/h