Physics
posted by Maxx .
A 0.9 kg object that stretches a spring 2.5 cm
from its natural length when hanging at rest
oscillates with an amplitude of 8.1 cm.
Find the total energy of the system. The
acceleration due to gravity is 9.81 m/s2.
Answer in units of J

The total energy is
E = (1/2)k*X^2
where X is the oscillation amplitude, 0.081 meters.
k is the spring constant,
(0.9)*(9.81)N/0.025 m = 352 N/m