A object of mass M1 travels in a circular path of radius R on a horizontal table. The object is attached to a string that passes through a hole in the center of the table. An object of mass M2 is attached to the other end of the strings and hangs vertically under the table, which produces a force on M1. All frictional forces are considered to be negligible. Which quantity or quantities must be measured to be determined the tangential speed required to keep the system in equilibrium