Q. A 0.5 kg ball is thrown up with an initial speed $14\ ms^{- 1}$ and reaches a maximum height of 8 m. How much energy is dissipate by air drag acting on the ball during the ascent?
A) 19.6 J
B) 4.9 J
C) 10 J
D) 9.8 J
Explanation
(d) Energy supplied $= \frac{1}{2}mv^{2} = \frac{1}{2}(0.5)14^{2} = 49\ J$
Energy stored $= mgh = 0.5 \times 9.8 \times 8 = 39.2\ J$
$\therefore$ Energy dissipated $= 49 - 39.2 = 9.8\ J$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.