CONCEPT:Equivalent stiffness of spring for series combination:\(\FRAC{1}{{{S_{eq}}}} = \frac{1}{{{S_1}}} + \frac{1}{{{S_2}}}\)\(\frac{1}{{{S_{eq}}}} = \frac{{({S_1} + {S_2})}}{{{S_1}{S_2}}}\)\({S_{eq}} = \frac{{{S_1}{S_2}}}{{({S_1} + {S_2})}}\)But here S1 = S2 = STherefore, \({S_{eq}} = \frac{{{S}{S}}}{{({S} + {S})}}=\frac{S^2}{2S}\)\(\Rightarrow S_{eq}=\frac{S}{2}\)Equivalent stiffness of spring for parallel combination:Seq = S1 + S2