Two identical springs of force constant "k" are joined one at the end of the other (in series). Find the effective force constant of the combination.

Explanation

When two springs of constant k each are joined together with end in series then effective spring constant `k=(k_(1)k_(2))/(k_(1)+k_(2))` in this case `k_(eq)=(k.k)/(k+k)=(k)/(2)`
In series combination, force constant of springs decreases.