A stepped pulley consists of two joined solid cylinders: an outer cylinder of radius \(R\) and an inner cylinder of radius \(r\). The pulley has a total rotational inertia \(I\) and mass \(M_p\), and it is mounted on a frictionless horizontal axle. A block of mass \(m\) is suspended from a lightweight string wrapped around the right side of the outer cylinder. A student holds a second lightweight string wrapped around the left side of the inner cylinder. The student pulls downward on the second string with a constant force \(F_A\). Neither string slips on the pulley.