A string is wrapped around a pulley with a radius of 2.0 cm. The pulley is initially at rest. A constant force is 50N is applied to the string, causing the pulley to rotate and the string to unwind. The string unwinds 1.2 m in 4.9 s. (a) Find the angular acceleration at which the string unwinds. (b) What is the moment of inertia of the pulley. Please show me step by step. Please show show me all the units throughout the problem. Thanks!