A 5-kg mass hangs at the end of a spring whose constant is k=400 N/m. The mass is displaced a distance of 25 cm and released. A) What is the

A 5-kg mass hangs at the end of a spring whose constant is k=400 N/m. The mass is displaced a distance of 25 cm and released.

A) What is the acceleration at the instant the displacement is x=+9 cm?

B) What is the Maximum acceleration and at what displacement does it occure?

Please show your work and explain how you got the answer! Thank you!! :)