Question

A flywheel gains a speed of $540rpm$ in $6$ sec. Its angular acceleration will be :

• A. $3\pi rad{s}^{-2}$
• B. $9\pi rad{s}^{-2}$
• C. $18\pi rad{s}^{-2}$
• D. $54\pi rad{s}^{-2}$

Answer 1

Answer: (A)

From first equation of circular motion, we get

$\omega ={\omega }_0+\alpha t$

$\alpha =\frac{\omega -{\omega }_0}{t}$

$=\frac{5400\times 2\pi }{60\times 60}$

$=3\pi rad/s^2$