If force $P=15N,$ determine the magnitude of the force in the spring. The spring constant is NOT given. Note the force in CD is $50N$ in compression when $P=15N$

$F_{\text{s}\text{p}\text{r}\text{i}\text{n}\text{g}}=16\mathrm{.}8N$

$F_{\text{s}\text{p}\text{r}\text{i}\text{n}\text{g}}=10\mathrm{.}7N$

$F_{\text{s}\text{p}\text{r}\text{i}\text{n}\text{g}}=21\mathrm{.}4N$

$F_{\text{s}\text{p}\text{r}\text{i}\text{n}\text{g}}=14\mathrm{.}1N$