A force $F(x)=-4\mathrm{.}5(\frac{N}{m})x+9(N)$ is acting on a body with a mass of $2$ kg and total energy of $18$ J $.$

$11.$ Which of the following can be the potential energij of this firce?

$(4)2\mathrm{.}25(\frac{N}{m})x^2-9(N)x-9($J$)$

$($b$)9(\frac{N}{m})x^2+9(N)x-9(J)$

$($e$)9(\frac{N}{m})x^2+9(N)x$

$($c$)2\mathrm{.}25(\frac{N}{m})x^2+9(N)x$

$($c$)2\mathrm{.}25(\frac{N}{m})x^2+9(N)x-9(J)$

$12.$ Find the stable equilibrium position of the body.

$($R$)4\mathrm{.}5$ m

$(8)2$ m

$($c$)4$ m

$($d$)3$ m

$($e$)9$ m

$13.$ Find the minimum and marimum values of $x$ that the body reaches in its motion.

$($a$)I_{\text{m}\text{i}\text{n}}=1,x_{\text{m}\text{a}\text{x}}=3$

$($b$)x_{\text{m}\text{i}\text{n}}=2,x_{\text{m}\text{a}\text{x}}=6$

$($c$)$ Xmin$=2,I_{\text{t}\text{a}\text{c}\text{k}}=3$

$($af $x_{\text{m}\text{i}\text{n}}=-2*x_{\text{m}\text{a}\text{x}}=6$

$($c$)x_{\text{m}\text{i}\text{n}}=-1,I_{\text{m}\text{a}\text{x}}=3$

$14.$ For what value of $x$ the kinetic energy is maximum?

$($a$)2$ m

$($b$)4$ m

$($c$)5$ m

$($d$)3$ m

$($e$)9$ m

$15.$ Find the maximum speed of the body.

$($a$)2\frac{m}{s}$

$($b$)3\frac{m}{s}$

$($g$)6\frac{m}{s}$

$($d$)9\frac{m}{s}$

$($e$)8\frac{m}{s}$