Q. A body of mass 2 kg attached to a string is whirled in a vertical circle of radius 5 m. The minimum speed of the body at lowest point so that the cord does not slacken even at the highest point is
A) 15.65 $ms^{- 1}$
B) 6.75 $ms^{- 1}$
C) 20.87$\ ms^{- 1}$
D) 45.83$\ ms^{- 1}$
Explanation
(a) Minimum speed at the lowest point
$= \sqrt{5rg} = \sqrt{5 \times 5 \times 9.8} = 15.65\ ms^{- 1}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.