Q106 / 180 · JIPMER 2019 · Physics
If object starts from rest and covers angle of 60 rad in 10 sec in circular motion magnitude of angular acceleration will be
- Correct answerA$1.2 \mathrm{rad} / \mathrm{sec}^2$
- B$1.5 \mathrm{rad} / \mathrm{sec}^2$
- C$2 \mathrm{rad} / \mathrm{sec}^2$
- D$2.5 \mathrm{rad} / \mathrm{sec}^2$
Solution
Given, initial angular velocity of object $w_0=0$
Angular displacement $\theta=60 \mathrm{rad}$
and
$\Delta \mathrm{t}=10 \mathrm{sec}$
From equation of rotational motion,
$\begin{aligned}
\theta & =\mathrm{w}_0 \mathrm{t}+\frac{1}{2} \alpha \mathrm{t}^2 \\
60 & =0 \times \mathrm{t}+\frac{1}{2} \times \alpha \times 10^2 \\
\Rightarrow \quad \alpha & =\frac{60}{50} \Rightarrow \alpha=1.2 \mathrm{rad} / \mathrm{s}^2
\end{aligned}$
Hence, the correct answer is option: 'A'.