Question

A car travels from stop A to stop B with a speed of 30 km/hr and then returns
back to A with a speed of 50km/hr. Find :
1) Displacement of the car
2) Distance travelled by the car
3) Average speed of the car​

Answer 1

We know that displacement is the shortest path covered by the object and if that car comes in its original position then the displacement of the car will be zero no matter what is the speed

Total distance travelled is is from stop a to b and from B to again a

Average speed is the total distance upon total time taken

I think that any data is missing

Answer 2

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