A toy top has a string wrapped around its body. The string has a length of 64cm and is wrapped around the top at a place where its radius is 2.0cm. The thickness of the string is negligible. The top is initially at rest. Someone pulls the free end of the string, thereby unwinding it and giving the top an angular acceleration of 12 rad/s^2. What is the final angular velocity in rpm of the top when the string is completely unwound?