Question $1$

$($a$)$ An actuating system consisting of an extension shape memory alloy $($SMA$)$ spring and a bias steel spring in a frictionless pin$-$joint is shown in Figure Q$1($a$).$ The system supports a constant load of $1$ N at the point A which moves over a distance of $50$ mm at the temperature $A_f.$ The bias spring having original length of $35$ mm and spring rate of $0\mathrm{.}1\frac{N}{m}m$ will then pull the lever$-$bar back when SMA spring is below $M_f($cold$).$ If the force due to bias spring is $1\mathrm{.}5$ N $,$ the total load on the SMA spring is $6\mathrm{.}5$ N $.$ The shear moduli of the SMA spring at $M_f$ and $A_f$ are $2,700$MPa and $24,500$MPa, respectively, while the low temperature $(c{}_c$ temperature