Question

The angular speed of a fly wheel making $120$ revolutions/minute is

• A. $2\pi rad/s$
• B. $4{\pi }^{2}rad/s$
• C. $\pi rad/s$
• D. $4\pi rad/s$

Answer 1

Answer: (D)

$4\pi rad/s$

Angular speed of a fly wheel, $W=2n\Pi$

$\Rightarrow W=2\Pi \times \frac{120}{60}$ rad/s

$\Rightarrow W=4\Pi$ rad/s

$\therefore$ Ans is D.