A box containing a pebble is attached to an ideal horizontal spring and is oscillating on a friction-free air table. When the box has reached its maximum distance from the equilibrium point, the pebble is suddenly lifted out vertically without disturbing the box. Will the following characteristics of the motion increase, decrease, or remain the same in the subsequent motion of the box? Justify each answer.

(a) Frequency;

(b) Period;

(c) Amplitude;

(d) The maximum kinetic energy of the box;

(e) The maximum speed of the box.