An object of mass m1 sliding on a frictionless horizontal surface is attached to a spring of force constant k and oscillates with an amplitude A. When the spring is at its greatest extension and the mass is instantaneously at rest, a second object of mass m2 is placed on top of it.

(a) What is the smallest value for the coefficient of static friction ms such that the second object does not slip on the first?

(b) Explain how the total energy E, the  amplitude A, the angular frequency w, and the period T of the system are changed by placing m2 on m1, assuming that the friction is great enough so that there is no slippage.