Answer:
ω = (m / k)^1/2 frequency of vibration
x = A sin ω t displacement of body at time t
P = 1 / f = 2 π / ω since ω = 2 π f
ω = 2 π / P = 2 π / .2 = 10 * 3.14 = 31.4 / sec
Since a(max) = A ω^2 maximum acceleration
a(max) = .0763 * 31.4^2 = 75.2 m/s^2
F = m a = .497 * 75.2 = 37.4 N maximum force