Question

A wheel has angular acceleration of $3.0 \,rad/sec^{-2}$ and an initial angular speed of $2.00\, rad\,s^{-1}$. In a time of $2\, s$ it has rotated through an angle (in radian) of

• A. 10
• B. 12
• C. 4
• D. 6

Answer 1

Answer: (A)

Given: Angular acceleration, $\alpha=3 \,rad / \sec ^{2}$
Initial angular velocity $\omega_{i}=2 \,rad / \sec$
Time $t=2 sec$
Using, $\theta=\omega_{i} t+\frac{1}{2} \alpha t^{2}$
$\therefore \theta=2 \times 2+\frac{1}{2} \times 3 \times 4$
$=4+6=1 0 $ radian