Q. An athlete in the Olympic games covers a distance of 100 m in 10 s. His kinetic energy can be estimated to be in the range
A) $2 \times 10^{5}J - 3 \times 10^{5}J$
B) $20,000\ J - 50,000\ J$
C) $2,000\ J - 5,000\ J$
D) $200\ J - 500\ J$
Explanation
(c) Average velocity $= \frac{100}{10} = 10\ m/s$
$K.E. = \frac{1}{2}m \times v^{2} = \frac{1}{2}m \times (10)^{2}$
If $m = 40\ kg$, then $K.E. = 2000\ J$. If $m = 100kg$, then $K.E.\ = 5000\ J$
So range will be $2000J - 5000J$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.