Problem No$.2(30$ points$)$

A plastic bar of diameter $d=25mm$ is compressed in a testing device by a force $P=110N$ applied as shown below.

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e

e

B

Next Time

$=\frac{d^2}{4}$

$=(\frac{}{25}[(mm)){)}^2$

Now choose the appropriate answer for the following question based the above information

$2\mathrm{.}1.$ The axial force in the plastic bar is

$($A$)110$ N compression

$($B$)110$ N tension

Axial Force Must pass

$($C$)440$ N Compression

$($D$)440$ N tension

$($E$)$ None of the above through member Ex$.$

$2\mathrm{.}2.$ The Normal$-$stress in the plastic bar is

$($A$)-0\mathrm{.}896$ MPa

$($B$)-0\mathrm{.}224$ MPa

$($C$)0\mathrm{.}896$ MPa

$($D$)0\mathrm{.}224$ MPa

$$

$($E$)$ None of the above

$2\mathrm{.}3.$ Assuming the normal stress in the plastic bar to be $-1\mathrm{.}0$ MPa $,$ the shear stress on an element oriented at $=22\mathrm{.}5$ is

$($A$)-3\mathrm{.}54$ MPa

$($B$)-0\mathrm{.}354$ MPa

$($C$)-0\mathrm{.}854$ MPa

$($D$)-0\mathrm{.}446$ MPa

$($E$)$ None of the above

${}_0=\frac{,sin(2)}{2}=\frac{-1[M{P}_a]sin(45)}{2}$

$=-0\mathrm{.}354[M*P_a]$

$2\mathrm{.}4.$ Assuming the normal stress in the plastic bar to be $-1\mathrm{.}0$ MPa $($for the plane perpendicular to axis of bar$),$ the normal stress on an element oriented at $=22\mathrm{.}5$ is

$($A$)3\mathrm{.}54$ MPa

$($B$)-0\mathrm{.}354$ MPa

$($C$)-0\mathrm{.}854$ MPa

$($D$)-0\mathrm{.}446$ MPa

$($E$)$ None of the above

${}_{}=\frac{{}_{x}sin(2)}{2}$

$2**21$