# If a spring has a constant of 9 (kg)/s^2, how much work will it take to extend the spring by 22 cm ?

$W = \frac{1}{2} \cdot F \cdot e$
The relationship between force and extension is given by $F = k \cdot e$
$W = \frac{1}{2} \cdot k \cdot {e}^{2}$
$W = \frac{1}{2} \cdot 9 \cdot {0.22}^{2} = 0.22 J$