Question

A wheel has angular acceleration of $3rad/s^2$ and an initial angular speed of $2rad/sec.$ In a time of $2sec$ it has rotated through an angle of $($in radians$)?$

• A. $10rad$
• B. $20rad$
• C. $15rad$
• D. $25rad$

Answer 1

The correct option is A $10rad$

$\begin{array}{c}Theangularaccelerationis\alpha =3rad{s}^{-2}\\ Theinitialangulaspeedis{\omega }_0=2rad{s}^{-1}\\ Thetimeist=2s\\ Applytheequation\theta ={\omega }_{0}t+\frac{1}{2}\alpha t^2\\ Theangleis\\ \theta =2\cdot 2+\frac{1}{2}\cdot 3\cdot 2^2=4+6\\ =10rad\end{array}$

Hence,

option $\left(A\right)$ is correct answer.