4. A mass m undergoes circular motion of radius R on a horizontal frictionless table, connected by a massless string through a hole in the table to a second mass m2. If m2 is stationary, find expressions for (a) the string tension, (b) the velocity of m, and (c) the time it takes for m to go around once (i.e., the period). Express your answer in terms of the masses, mi and m2, 9, and the radius of the cir- cle, R, and not the velocity, v of m. m2 R mi