Two springs of force constant 2000 N/m and 4000 N/m are stretched by same force. The ratio of their respective potential energies is
2:1
1:2
4:1
1:4
PE of mass attached to a spring is PE=12kx2, where k= force constant, x= displacement restoring force of a spring is F=-kx, ⇒ x=-Fk,substitute in PE equation PE=12kFk2 ⇒PE=12kF2k2 ⇒PE =12F2k ⇒PEα1k since stretched by same force ⇒PE1PE2=k2k1=40002000=21 obtained after substituting the given values of force constant k1,k2