You will need
  • spring any a weight of 100 grams, ruler
It should vertically to fasten the spring. Measure with a ruler the length of the spring before it hang the cargo during the suspension of weight on it. Calculate the difference of the lengths of the springs. It turns out that x = x1-x2, found elongation of the spring.
Mounted on the spring any a weight of 100 grams. This weight acts on the spring with a force equal to 1 Newton. Therefore, the second value is already known. F= 1N.
According to Hooke's law to find the stiffness coefficient of the spring, it is necessary to divide the tensile force of a spring on its lengthening. k=F/x. These two values are already defined empirically.