Q 11-02-006NEETNEET 2023Top questionEasy
A vehicle travels half the distance with speed $\vartheta$ and the remaining distance with speed $2\vartheta$. Its average speed is:
Answer: (C) $\dfrac{4\vartheta}{3}$
Let the total distance be $2d$. Time taken:
$$t = \frac{d}{\vartheta} + \frac{d}{2\vartheta} = \frac{3d}{2\vartheta}$$
$$\text{Average speed} = \frac{2d}{3d/(2\vartheta)} = \frac{4\vartheta}{3}$$
Solution by Sreeraj P, M.Sc Physics