Question

A wheel of radius $0.20m$ is mounted on a frictionless horizontal axis. The rotational inertia of the wheel about the axis is $0.07kg{m}^2$. A massless cord wrapped around the wheel is attached to a $2.0kg$ block that slides on a horizontal frictionless surface. If a horizontal force of magnitude $P=3.0N$ is applied to the block as shown in figure, what is the magnitude of the angular acceleration (in $r/s^2$ ) of the wheel? Assume the string does not slip on the wheel.

Answer 1

Answer: 4

$P-T=ma$...(i)
$TR=I_C\alpha$...(ii)
$a=\alpha R$...(iii)

$P=\frac{I_C}{R}\alpha +m\alpha R$
$\therefore \alpha =4r/s^2$