Question

two cars are moving in the same direction with the same velocity of 50 kmph .they are separated by distance of 2km what is the speed of a car moving in the opposite direction if it meet the two cars at an interval of 1 minute​

Answer 1

Let the instant when the cars meets the first time be t - 0s

Then , with respect to third car ( with say velocity V)

Velocity of approaching car = ( 30 +V) km / hr

Distance of separation= 4km

Time to cover separation= 5 min =1/2 hr

Then, (30+V) = 4km / (1/12) hr

= 30+ V = 4 into 12

V= 48 - 30 = 18 km /hr

The speed of car moving in opposite direction is 18 km/hr.