Questions $7-9(30$ points$)$ A torsion spring is used in a hand$-$held spring clamp. The jaws of the clamp are $1\mathrm{.}5$ inches from the pivot. The spring angle is $45$ when the clamp is closed and $0$ when the clamp is open. Use units of torque$/$rev for torsional spring constant. Include leg length in $N_a$ calculations.

$d=0\mathrm{.}078$ in $,OD=0\mathrm{.}396$ in $,N_b=3\mathrm{.}25,{}_{\text{f}\text{r}\text{e}\text{e}}=90,$ music wire legs $L_1=L_2=1\mathrm{.}5$ in

$(10$ points$)$ Determine the torsional spring constant in units of in$-$lbf$/$rev$.$

$(10$ points$)$ Determine the clamping force when closed in units of lbf$.$

$(10$ points$)$ Determine the clamping force when open in units of lbf$.$