Question

A motorcyclist drives from a to b with a uniform speed of 50km/h and returns back with a speed of 20km/h. Find its average speed.

Answer 1

Explanation:-

A motorcyclist drives from point A to point B , with an uniform velocity

50 km/h to 20 km/h

so ,let the total distance travelled be X

now ,the time taken by the motorcyclist to travel from the point A to point B be X/50 Hours

And the time taken by the motorcyclist to travel from the point B to point A be X/20 Hours

so the total time taken is = to

{X/50+ X/20 } Hours

T= 70X/1000 [ T= total time]

And the total distance traveled is = to X + X

Now,

Average speed =

Total distance / Total time

Average speed= {X+ X÷ X/50 + X/20}

Average speed = {2X ÷ 70X/1000}

Average speed = {2 ÷ 70/1000}

Average speed = { 2 × 1000/70}

Average speed = 2000/70

Average Speed = 28.57 km/h

Hence the average speed of the

motorcyclist is 28.57 km/h