Answer:
a) the total circle of "initial" is Epot./Eel. and the total circle of "final" is Ekin.
b)intia: 0.5 * 50 * 4^2 = 400 J
final: 0 J = 0.5 * 50 * 0^2
Explanation:
c) in the first phase the spring is (pressed or forced into a smaller space) and so has Epot but then the Energie changes to be totally Ekin (in final phase) and so the Epot becomes 0
