Chapter 12, Problem 67P

An object of mass m₁ = 9.00 kg is in equilibrium when connected to a light spring of constant k = 100 N/m that is fastened to a wall as shown in Figure P12.67a. A second object, m₂ = 7.00 kg, is slowly pushed up against m₁, compressing the spring by the amount A = 0.200 m (see Fig. P12.67b). The system is then released, and both objects start moving to the right on the frictionless surface. (a) When m₁ reaches the equilibrium point, m₂ loses contact with m₁ (see Fig. P12.67c) and moves to the right with speed v. Determine the value of v. (b) How far apart are the objects when the spring is fully stretched for the first time (the distance D in Fig. P12.67d)?

Figure P12.67