# If a spring has a constant of 10 (kg)/s^2, how much work will it take to extend the spring by 40cm ?

I found: $0.8 J$
$W = \frac{1}{2} k {x}^{2} = \frac{1}{2} \cdot 10 \cdot {\left(0.4\right)}^{2} = 0.8 J$