A coiled Hookean spring is stretched 10 cm when a 1.5-kg body is hung from it. Suppose instead that a 4.0-kg mass hangs from the spring and is set into vibration with an amplitude of 12 cm. Find 

(a) The force constant of the spring, 

(b) The maximum restoring force acting on the vibrating body, 

(c) The period of vibration, 

(d) The maximum speed and the maximum acceleration of the vibrating object, and 

(e) The speed and acceleration when the displacement is 9 cm.