The force constants of two springs are K1 and K2. Both are stretched till their elastic energies are equal. If the stretching forces are F1 and F2 , then F1:F2 is
K1:K2
K2:K1
K12:K22
Given elastic energies are equal i.e., 12k1x12=12k2x22⇒k1k2=x2x12 and using F=kx
⇒F1F2=k1x1k2x2=k1k2×k2k1=k1k2