Q. A particle covers half of its total distance with speed $v_{1}$ and the rest half distance with speed $v_{2}$. Its average speed during the complete journey is
A) $\frac{v_{1}^{2}v_{2}^{2}}{v_{1}^{2} + v_{2}^{2}}$
B) $\frac{v_{1} + v_{2}}{2}$
C) $\frac{v_{1}v_{2}}{v_{1} + v_{2}}$
D) $\frac{2v_{1}v_{2}}{v_{1} + v_{2}}$
Explanation
(d) $V_{av} = \frac{S + S}{\frac{S}{v_{1}} + \frac{S}{v_{2}}} = \frac{2v_{1}v_{2}}{v_{1} + v_{2}}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.