Q. A sphere is suspended by a thread of length $l$. What minimum horizontal velocity has to be imparted the ball for it to reach the height of the suspension
A) $gl$
B) $2gl$
C) $\sqrt{gl}$
D) $\sqrt{2gl}$
Explanation
(d) Kinetic energy given to a sphere at lowest point = potential energy at the height of suspension
$\Rightarrow \frac{1}{2}mv^{2} = mgl$
$\therefore v = \sqrt{2gl}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.