Force Constant (Spring Constant) #8211; We know that, defining equation of SHM is a = -ω<sup>2</sup> x, also a = F/m ∴ F/m = #8211; ω<sup>2</sup> x ⇒ F = -mω<sup>2</sup>x ⇒ (F = -kx) k is called spring constant or force constant. Also, k = mω<sup>2</sup>.