1. The problem statement, all variables and given/known data a steel spring that it extends by 10cm in equilibrium when you attach the upper end of the spring to a fixed support and hang a weight of 100g at the lower end. And I found k and T, so how about if I change the weight to 1kg at the lower end and do the same thing? 2. Relevant equations F = -kx 3. The attempt at a solution I found they actually same. when 100g mg=kx k=9.81 T=2pi*sqrt(m/k) = 2*pi*sqrt(0.1/9.81) = ... when 1kg mg=kx k = 98.1 T=2pi*sqrt(m/k) = 2*pi*sqrt(1/98.1) = ... same!? I think I did wrong, who can help me? THANK YOU!