Question

A 10.-newton force is required to hold a stretched spring 0.20 meter from its rest position. What is the potential energy stored in the
stretched spring?

Answer 1

Data: 
Ep = ? (Joule)
if: F = k.x → F  = 10 N
x (displacement) = 0.20 m

Formula:
$Ep = \frac{F*x}{2}$

Solving:
$Ep = \frac{F*x}{2}$
$Ep = \frac{10*0.20}{2}$
$Ep = \frac{2}{2}$
$\boxed{\boxed{Ep = 1\:Joule}}\end{array}}\qquad\quad\checkmark$