Q 11-05-032NEETEAMCET 2007 (Medical)Easy
A body of mass $2$ kg is thrown up vertically with kinetic energy of $490$ J. If $g = 9.8\ \text{m/s}^2$, the height at which the kinetic energy of the body becomes half of the original value is
Answer: (C) $12.5$ m
Concept. Half the KE has become PE.
Step 1. Height. $mgh = 245 \Rightarrow h = \dfrac{245}{19.6} = 12.5$ m.
Answer. $12.5$ m (Option C).
Solution by Sreeraj P, M.Sc Physics