Q. A disc starting from rest acquires in 10 sec an angular velocity of 240 revolutions/minute. Its angular acceleration (assuming constant) is
A) $1.52\ rad/s$
B) $2.51\ rad/s$
C) $3.11\ rad/s$
D) $3.76\ rad/s$
Explanation
(b) $\alpha = \frac{\omega_{2} - \omega_{1}}{t} = \frac{2\pi(n_{2} - n_{1})}{t} = \frac{2\pi \times \left\lbrack \frac{240}{60} - 0 \right\rbrack}{10}$
$\therefore\alpha = 2.51\ rad/s$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.