1. The problem statement, all variables and given/known data A series of masses are hung from a vertical spring and the length is measured in each case to the nearest milimeter. Data below: Mass : Spring Length 050g : 40.2cm 100g : 45.8cm 150g : 50.9cm 200g : 56.4cm 250g : 61.4cm 300g : 66.9cm 350g : 73.7cm 400g : 81.2cm I need to find the spring constant. 2. Relevant equations Fs = k | l - l0| , where Fs = Spring Force k = spring constant l = length of spring l0 = initial length of spring 3. The attempt at a solution I know that Fs = Fg = mass / 100 (using g = 10 N/kg). I just don't know how to get the constant because I don't know what the initial spring length is (it's not 0).