Question

A torque of $30 \,N-m$ is acting on a wheel of mass $5 \,kg$ and moment of inertia $2\, kg-m2$. If wheel starts rotating from rest then, its angular displacement in $10$ seconds will be:

• A. 750 rad
• B. 1500 rad
• C. 3000 rad
• D. 6000 rad

Answer 1

Answer: (A)

750 rad

Answer 2

$\tau =I \alpha$ $30 =2 \times \alpha$ $\Rightarrow \alpha =15\, rad / sec ^{2}$ From equation of angular motion $\theta=\omega_{0} t+\frac{1}{2} \alpha t^{2}$ $=0+\frac{1}{2} \times 15 \times 10 \times 10$ $=750\, rad$