Stretching a spring A spring has a natural length of 10 in. An 800 -lb force stretches the spring to 14 in.
\begin{equation}
\begin{array}{l}{\text { a. Find the force constant. }} \\ {\text { b. How much work is done in stretching the spring from } 10 \text { in. }} \\ \quad {\text { to } 12 \text { in.? }} \\ {\text { c. How far beyond its natural length will a } 1600 \text { -lb force stretch }} \\ \quad {\text { the spring? }}\end{array}
\end{equation}