Q. A wheel completes 2000 revolutions to cover the $9.5\ km.$ distance. Then the diameter of the wheel is
A) $1.5\ m$
B) $1.5\ cm$
C) $7.5\ cm$
D) $7.5\ m$
Explanation
(a) Distance covered in $'n'$ revolution = $n$ 2 $\pi r = n\pi D$
$\Rightarrow 2000\pi D = 9500\lbrack As\ n = 200,distance = 9500\ m\rbrack$
$\Rightarrow D = \frac{9500}{2000 \times \pi} = 1.5\ m$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.