Q. A $0.5\ kg$ ball is thrown up with an initial speed $14\ m/s$ and reaches a maximum height of $8.0m$. How much energy is dissipated by air drag acting on the ball during the ascent
A) $19.6\ Joule$
B) $4.9\ Joule$
C) $10\ Joule$
D) $9.8\ Joule$
Explanation
(d) If there is no air drag then maximum height
$H = \frac{u^{2}}{2g} = \frac{14 \times 14}{2 \times 9.8} = 10\ m$
But due to air drag ball reaches up to height $8m$ only. So loss in energy
$= mg(10 - 8) = 0.5 \times 9.8 \times 2 = 9.8\ J$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.