UPPCS · પ્રશ્ન 71
A bus covers the first half of a certain distance with speed v1 and the second half with a speed v2. The average speed during the whole journey is:
જવાબ બતાવો અને સમજૂતી
જવાબ: (B) 2v1v2 / (v1 + v2)
સમજૂતી
Average speed = total distance / total time = 2d / (d/v1 + d/v2) = 2v1v2/(v1 + v2), the harmonic mean.