Q. A body of mass 2 kg is thrown up vertically with kinetic energy of 490 J. The height at which the kinetic energy of the body becomes half of its original value is?
A) 50 m
B) 12.25 m
C) 25 m
D) 10 m
Explanation
(b) Potential energy at the required height
$= \frac{490}{2} = 245\ J$
Again, 245=2$\times 10 \times h$ or $h = \frac{245}{20}m = 12.25\ m$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.