Q. An unbanked curve has a radius of 60 m. The maximum speed at which the car make a turn is (Take $\mu = 0.75$)
A) 7$\ ms^{- 1}$
B) 14$\ ms^{- 1}$
C) 21$\ ms^{- 1}$
D) 2.1$\ ms^{- 1}$
Explanation
(c) From $\frac{mv^{2}}{r} = F = \mu\ mg$
$\therefore v = \sqrt{\mu rg} = \sqrt{0.75 \times 60 \times 10} = \sqrt{450} = 21ms^{- 1}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.