Q. A bridge is in the form of a semi-circle of radius $40m$. The greatest speed with which a motor cycle can cross the bridge without leaving the ground at the highest point is $(g = 10\ ms^{- 2})$ (frictional force is negligibly small)
A) $40\ ms^{- 1}$
B) $20\ ms^{- 1}$
C) $30\ ms^{- 1}$
D) $15\ ms^{- 1}$
Explanation
(b) $v = \sqrt{gr} = \sqrt{10 \times 40} = 20ms^{- 1}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.