Question

15) A car travels from stop A to stop B with a speed of 30 km/h and then returns back to A with a
speed of 50 km/h. Find
i. displacement of the car.
ii. distance travelled by the car.
iii. average speed of the car.​

Answer 1

1. Displacement=0

Since it returned to the same place from where it started

2. Distance =Total distance covered by the car

3.Average speed=Total distance between A and B/Total time taken

Answer 2

Answer:

1. Displacement is zero

Explanation:

1. Displacement is zero because it come back where from it starts.

let distance A to B is x

and again back then it is 2x

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