Question

The rotating rod starts from rest and acquires a rotational speed $\omega =600rev/min$ in $2$ seconds with constant angular acceleration. The angular acceleration of rod is?

• A. $20\pi rad/s$
• B. $10\pi rad/s$
• C. $30\pi rad/s$
• D. $5\pi rad/s$

Answer 1

The correct option is B $10\pi rad/s$

Initial angular velocity $w_i=0$

Final angular velocity $w_f=600rev/min=600\times \frac{2\pi }{60}=20\pi rad/s$

Time $t=2s$

Using $w_f=w_i+\alpha t$

Or $20\pi =0+\alpha \times 2$

$⟹\alpha =10\pi rad/s$