If a spring of force constant 'K' is cut into three equal parts then the force constant of each part will be
K3
K
3K
6K
Force equation for mass attached to a spring is F=-kx where k is force constant and x is displacement of the mass
for a length l of spring equation of force is F=-kl---(1) when the spring is cut into 3 equal parts equation of force is F = -k1l3---(2) substitute (1) in (2) -kl = -k1l3 ⇒k1=3k alternate solution: ***** F=-kx ⇒k1l1=k2l2 kl=k2l3 so k2=3k