Also, the modulus of elasticity $E$ is $6\mathrm{.}0$ GPa $,$ and the

coefficient of thermal expansion $$ is $100\frac{{10}^{-6}}{}C.$

The bar is subjected to a uniform temperature

increase of $30C.$

$($a$)$ Calculate the following quantities: $(1)$ the com$-$

pressive force $N$ in the bar; $(2)$ the maximum

compressive stress ${}_c$; and $(3)$ the displacement

${}_C$ of point $C.$

$($b$)$ Repeat part $($a$)$ if the rigid support at $A$ is

replaced by an elastic support having spring

constant $k=50M\frac{N}{m}($see figure part b ;

assume that only the bar ACB is subject to the

temperature increase$).$