Two stones, P and Q, start falling simultaneously from the same balcony 50m above the ground. Stone P is simply dropped from rest, while stone Q is projected straight downward with an initial speed of 15m/s. Take g=10m/s2.
(a) Derive an expression for the separation between the two stones after any time ts from the instant of release.
(b) Using the expression obtained in part (a), determine the time when Q is exactly 25m below P.
(c) Calculate the velocities of P and Q at that instant, stating their directions.