Q. A boy whirl is a stone in a horizontal circle of radius 1.5 m and at height 2.0 m above level ground. The string breaks and the stone flies off tangentially and strikes the ground after traveling a horizontal distance of 10 m. What is the magnitude of the centripetal acceleration of the stone while in circular motion?
A) $163\ ms^{- 2}$
B) 64 $ms^{- 2}$
C) 15.63 $ms^{- 2}$
D) 125 $ms^{- 2}$
Explanation
(a) $t = \sqrt{\frac{2h}{g}} = \sqrt{\frac{2 \times 2}{9.8}} = 0.64\ $s
$v = \frac{10}{t} = 15.62\ ms^{- 1}$
$\therefore\ a = \frac{v^{2}}{R} = 163\ ms^{- 2}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.