Are car covers the first half of the distance between two places at a speed of 40 km per hour and the second half at 60 km per hour What is the average speed of the car?

A car covers the first half of the distance between two places at a speed of 40 km/h and the second half at 60 km/h. What is the average speed of the car?

Let, the total distance covered the car be 'd'. Given, Speed in the first half = 40 km/hrSpeed in the second half of distance = 60 km/hr

Let the time taken by the car in the first half = t1
Therefore, 

Time taken by car in the second half, t2 = d260=d120

Now, average speed = Total distance travelledTotal time taken

                              = dd80+d120= 80×12080+120= 9600200= 48 km/hr 

Text Solution

Solution : Given, speed in first half, `v_(1)=40 kmh^(-1)`. <br> Speed in second half, `v_(2) = 60 kmh^(-1)`. <br> `because` Car covers equal distance with different speeds. <br> `therefore` Average speed of car <br> `v_(av)=(2v_(1)v_(2))/(v_(1)+v_(2))` <br> `v_(av)=(2(40) (60))/(40+60)=48 kmh^(-1)`

A car covers the first half of the distance in 40 km / hr and the second half in 60 km / hr. what is the avrage speed of the car?

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