Question

A car moves with a speed of 30 km/h–1 for half an hour, 25 km/h–1 for one hour and 40 km/h–1 for two hours. Calculate the average speed of the car.

Answer 1

The average speed of the car is 34.28 km/h

Step-by-step explanation:

We have,

A car moves with a speed of 30 km/h for half an hour, 25 km/h for one hour and 40 km/h for two hours.

It is required to find the average speed of the car. It is equal to the total distance covered divided by total time taken.

Distance covered for half an hour is,
`d_1=30* (1)/(2)=15\ km`

Distance covered for one hour is,
`d_2=25* 1=25\ km`

Distance covered for two hours is,
`d_3=40* 2=80\ km`

Total distance is : 15 km + 25 km + 80 km = 120 km

Total time taken : 0.5 h + 1 h + 2 h = 3.5 h

Average speed :

`v=(d)/(t)\\\\v=(120)/(3.5)\\\\v=34.28\ km/h`

So, the average speed of the car is 34.28 km/h