How do you measure the ability of a substance to take compression? Do you use the force constant (k) of Hooke's law? F = -kx? For example, what propoerty correlates with a trampoline's ability to take compression better than a bed? Also, where can I find the force constant (k) of everyday items? More specificlly, Im looking for the force constant (k) of cooking corn starch, a non newtonain fluid? Does anyone know it?