Q 11-05-015NEETEAMCET 2014 (Medical)Easy
A body of $200$ g begins to fall from a height where its potential energy is $80$ J. Its velocity (in m/s) at a point where its kinetic and potential energies are equal is
Answer: (D) $20$
Concept. Total energy $80$ J; equal KE and PE means $40$ J each.
Step 1. Speed. $\dfrac12(0.2)v^2 = 40 \Rightarrow v = 20$ m/s.
Answer. $20$ (Option D).
Solution by Sreeraj P, M.Sc Physics