Question

A car travel at a velocity of 80 km/h during the
first half of its running time and at 40 km/h
during the other half. Find the average speed of
the car.
please answer step by step with formula​

Answer 1

$\huge \mathbb{\boxed{\red{Question\:}}}</p><p></p><p>$

A car travel at a velocity of 80 km/h during the first half of its running time and at 40 km/h during the other half. Find the average speed of the car.

$\huge{\red{\boxed{Solution}}}$

Given,

First Half of the running time - 80km/h

Second half of the running time - 40km/h

Then we have to find the average Speed.

Average Speed Formula:-

${\boxed{\red{Average \: speed \: = \frac{tota \: distance \: travelled}{time \: taken}}}}$

Average Speed = [80 + 40]/1/2 + 1/2

Average Speed = 120km/h

Answer 2

Let each half of the running time be t.

>>During the first half time, speed of the car os 80 km/hr.

Distance covered, $d_{1}$ = 80t km

>>During the second half time, speed of the car is 40 km/hr.

Distance covered, $d_{2}$ = 40t km

>>Total distance covered $d$ = $d_{1}+d_{2}$ = 80t + 40t =  120t

>>Total time taken $T$ = 2t

Average speed = $V_{avg}= \dfrac{d}{T} =\dfrac{120t}{2t} = 60 km/hr$

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