Hooke's Law formula  F = -k(d-d₀)
Where:
F: The Restoring Force, in Newton
d: Distance from Equilibrium, in meter
d₀: Spring Equilibrium Position, in meter
k: Spring Force Constant, in Newton.meter

Hooke's Law describes the restoring force exerted by the spring. The restoring force help the spring returns to its original configurtion after being distorted.