Q 11-02-089JEE MainJEE Main 2023 (1 Feb, Shift 1)Easy
An object moves with speed $v_1$, $v_2$ and $v_3$ along a line segment $AB$, $BC$ and $CD$ respectively as shown in figure, where $AB=BC$ and $AD=3AB$. Then average speed of the object will be
Answer: (C) $\dfrac{3v_1v_2v_3}{v_1v_2+v_2v_3+v_3v_1}$
All three segments have the same length $d$:
$$\bar v=\frac{3d}{\frac d{v_1}+\frac d{v_2}+\frac d{v_3}}=\frac{3v_1v_2v_3}{v_1v_2+v_2v_3+v_3v_1}$$
Solution by Sreeraj P, M.Sc Physics