Question

A car covers AB distance with first one-third at velocity v1 ms–1, second one-third at v2 ms–1 and last one-third at v3 ms–1. If v3 = 3v1, v2 = 2v1 and v1 = 11 ms–1 then the average velocity of the car is ____ ms–1.

Fig.

Answer 1

The correct answer is 18
$v_{mean} =\frac{3v_1v_2v_3}{v_1v_2+v_2v_3+v_3v_1}$
$=\frac{3×11×22×33}{11×22+22×33+33×11}$
= 18 m/sec