Q. An electric fan has blades of length 30 cm as measured from the axis of rotation. If the fan is rotating at 1200 rpm, the acceleration of a point on the tip of the blade is about
A) $1600\ {ms}^{- 2}$
B) $4740\ {ms}^{- 2}$
C) $2370\ {ms}^{- 2}$
D) $5055\ {ms}^{- 2}$
Explanation
(b) $Given,\ \ \ f = 1200\ rpm,$
$r = 30\ cm = \frac{30}{100}m$
Acceleration of a point at the tip of the blade
= centripetal acceleration
$= \ \omega^{2}r = (2\pi f)^{2}r$
$= \left( 2 \times \frac{22}{7} \times \frac{1200}{60} \right)^{2} \times \frac{30}{100}$
$= 4740\ {ms}^{- 2}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.