relevant equations: F = k*x F is force, k is spring constant and x is displacement from equillibrium.
W = 1/2kx2 W is work done.
rearranging F = k*x and using the information in the question we can solve for the spring constant: k = -600N/0.01m = 60000N/m. Remember to convert cm to m.
To find the work done we substitue the spring constant and the displacement distance of 10cm in to the equation for work done remembering to convert to SI units. W = 1/2*(60000N/m)(-0.01m)2 = 3J.
So the spring constant k is equal to 60000N/m and the work done is 3J