Answer Happy

please answer (f) with detailed explanation.
9. A 2.4-kg object on a frictionless horizontal surface is attached to a horizontal spring that has a force constant 4.5 kN/m. The spring is stretched 10 cm from equilibrium and released. What are (a) the frequency of the motion, (b) the period, (c) the amplitude, (d) the maximum speed, and (e) the maximum acceleration? (b) When does the object first reach its equilibrium position? What is its acceleration at this time? Ans: (a) f=6.89Hz (b)T=0.15s (c) A=10cm (d) 4.3m/s (e) 190m/s2