Two particles of masses m 1 and m 2 are joined by a massless spring of natural length l and force constant k. initially, m2 is resting on a table and i am holding m 1 vertically above m 2 at a height l. at time t = 0, i project m 1 vertically upward with initial velocity v o . find the positions of the two masses at any subsequent time t (before either mass returns to the table).