Question

A spring-loaded toy uses a compressed spring to fire a marble out of a
tube. A force of 220 N compresses the spring by 0.14 m. Calculate the
elastic potential energy of the toy.

Answer 1

Using the knowledge that the elastic potential energy of a spring is equal to the area under an F vs x graph (which is where the equation Ee = 1/2 kx^2 comes from);
Elastic potential energy = 1/2 xF
So,
Elastic potential energy = 1/2 (0.14)(220)

Answer 2

Using the knowledge that the elastic potential energy of a spring is equal to the area under an F vs x graph (which is where the equation Ee = 1/2 kx^2 comes from);
Elastic potential energy = 1/2 xF
So,
Elastic potential energy = 1/2 (0.14)(220)
= 15.4
=15 J