Answer:
x = A sin ω t    describes the displacement of the particle
v = A ω cos ω t
a = -A ω^2 sin ω t    Â
a (max) = -A ω^2   is the max acceleration (- can be ignored here)
ω = (K/ m)^1/2     for SHM
F = - K x^2 Â Â restoring force of spring
K = 4.34 / .0745^2 = 782 N / m
ω = (782 / .297)^1/2 = 51.3 / sec
a (max) = .0745 * 782 / .297 = 196 m / s^2