Q. The minimum velocity (in $ms^{- 1}$) with which a car driver must traverse a flat curve of radius 150 m and coefficient of friction 0.6 to avoid skidding is
A) $60\ ms^{- 1}$
B) 30$\ ms^{- 1}$
C) 15$\ ms^{- 1}$
D) 25$\ ms^{- 1}$
Explanation
(b) Using the relation
$\frac{mv^{2}}{r} = \mu R,R = mg$
$\frac{mv^{2}}{r} = \mu mg$ or $v^{2} = \mu rg$
or $v^{2} = 0.6 \times 150 \times 10$
or $v = 30\ ms^{- 1}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.