# If a spring has a constant of 2 (kg)/s^2, how much work will it take to extend the spring by 87 cm ?

Mar 14, 2018

$\text{0.76 Joule}$

#### Explanation:

Energy stored in a spring is given by

$U = \frac{1}{2} \setminus {\text{kx}}^{2}$

Energy stored in spring when it’s streched by $\text{87 cm}$ is

$U = \frac{1}{2} \setminus \text{kx"^2 = 1/cancel(2)\ cancel(2)\ "kg/s"^2 × ("0.87 m")^2 = "0.76 Joule}$

Work = ${U}_{f} - {U}_{i} = \text{0.76 J - 0 J = 0.76 J}$