Browse Questions
+1 vote

# It takes 100J of work to stretch a spring 0.5m from its equilibrium position.How much work is needed to stretch it an additional 0.75m?

$\begin{array}{1 1}525J\\625J\\725J\\325J\end{array}$

$100 =\int_0^{0.5} kxdx$
$\quad\;\;\;= \large\frac{1}{8}$$k$
$\Rightarrow k=800$
$W=\int\limits_{0.5}^{1.25} kxdx$
$\;\;\;\;=(400x^2)\bigg|_{0.5}^{1.25}$
$\;\;\;\;=525J$