Q. A body of mass $2\ kg$ slides down a curved track which is quadrant of a circle of radius $1\ metre$. All the surfaces are frictionless. If the body starts from rest, its speed at the bottom of the track is
A) $4.43\ m/sec$
B) $2\ m/sec$
C) $0.5\ m/sec$
D) $19.6\ m/sec$
Explanation
(a) By conservation of energy, $mgh = \frac{1}{2}mv^{2}$
$\Rightarrow v = \sqrt{2gh} = \sqrt{2 \times 9.8 \times 1} = \sqrt{19.6} = 4.43\ m/s$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.