Question

rohan comes to school from house with speed of v1 and returns back with speed of v2 . find its average speed during the whole journey

Answer 1

Let's assume that the distance between his home and his school is D km

Now
Avg speed = total distance covered / total time taken
$Savg= \frac{D+D}{ \frac{D}{V1} + \frac{D}{V2} }$
$Savg= \frac{2}{ \frac{1}{V1} + \frac{1}{V2} }$
$Savg= \frac{2V1V2}{ V1+V2 }$

Answer 2

HEY!!

______________________________

▶Formula of Speed= Distance/Time

▶Let the distance covered by Rohan from home to his school be X km

▶Average speed = X+X / X/V1+X/V2

▶Average Speed = 2 / 1/V1+1/V2

✔✔Average Speed = 2V1 V2/V1 + V2