Question

A car travel from stop a to bwith a speed of 30km/h and back to a with 50km/h find distance travelled by the car

Answer 1

Let the distance from A to B be x.

Then displacement of the car when it comes back to the same position is zero.

Distance travelled is 2x.

Time taken by the car when it moves from A to B is given by

t1 = Distance/Speed = x/30

Time taken by the car when it moves from B to A,

t2 = Distance/Speed = x/50

Total distance = 2x

Total time

= t1 + t2

= x/30 + x/50

= (5x + 3x)/150

= 8x/150

So, Average speed

= Total distance/Total time

= 2x/(8x/150)

= 37.5 km/hr

Answer 2

let a to b distance is x

t1=x/30

and t2=x/50

then distance =speed .time

x= 80.x/50.x/30

x=150/80

x=1.8. meter