Q. A 3 kg body is dropped from the top of a tower of height 135 m. If $g = 10\ ms^{- 2}$, then the kinetic energy of the body after 3 s will be
A) 950 J
B) 10 J
C) 1150 J
D) 1350 J
Explanation
(d) $h = 0 \times 3 + \frac{1}{2} \times 10 \times 3 \times 3 = 45\ m$
Loss of PE $= \ 3 \times 10 \times 45\ J = \ 1350\ J$
this will be the kinetic energy at $t = 3$ s
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.