Question

A uniform disc of mass $m$, radius $R$ is placed on a smooth horizontal surface. If we apply a horizontal force $F$ at $P$ as shown in the fig. If $F=4N$, $m=1kg$, $R=1m$ and $r=1/2m$ then, find the angular acceleration of the disc (rads−1)(rads−1)

Answer 1

$\tau =I\alpha \Rightarrow Fr=\frac{1}{2}m{R}^2\alpha \Rightarrow \alpha =\frac{2Fr}{m{R}^2}\Rightarrow \alpha =\frac{2\times 4\times \frac{1}{2}}{1\times 1^1}=4rad/s^2$