A fixed pulley of radius $20\,\text{cm}$ and moment of inertia $0.32\,\text{kg·m}^2$ about its axle has a massless cord wrapped around its rim. A mass $M$ of $2\,\text{kg}$ is attached to the end of the cord. The pulley can rotate about its axis without any friction. The acceleration of the mass $M$ is (take $g = 10\,\text{m/s}^2$)