The power ( sic .) of any springy body is in the same proportion with the extension.
announced the birth of elasticity. Hooke's statement expressed mathematically is,
F = k . x
where F is the applied force (and not the power, as Hooke mistakenly suggested), x is the deformation of the elastic body subjected to the force F , and k is the spring constant (i.e. the ratio of previous two parameters).