Question

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 traveled by car.
(iii) the average speed of the car

Answer 1

Answer:

Explanation:

Given :-

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.

To Find :-

(i) displacement of the car.

(ii) distance traveled by car.

(iii) the average speed of the car

Solution :-

Let the distance from A to B be x.

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

Distance traveled 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

⇒ Total time = x/30 + x/50

⇒Total time = (5x + 3x)/150

⇒ Total time = 8x/150

Now,

Average speed = Total distance/Total time

⇒ Average speed = 2x/(8x/150)

⇒ Average speed = 37.5 km/h

Hence, average speed of the car is 37.5 km/h.

Distance Traveled = 2x = 37.5 × 2 = 75 km

Hence, the distance traveled by car is 75 km.