QUESTION $2($CHAPTER $2)$

$($a$)$ A solid bar in tension or compression is found to exhibit a strain of $0\mathrm{.}00045,$ given as a dimensionless quantity but essentially the same as expressing it in or $\frac{m}{m}).$ This strain however can be expressed in two other different ways than the above dimensionless or $m\frac{m}{m}m$ or $\frac{m}{m}$ format.

i$.$ What kind of strain is given $0\mathrm{.}00045$ strain? $[2$ Marks$]$

ii$.$ Give one type of strain to which the above strain is different and discuss the difference in terms of deformations caused and the manner of measuring the deformations.

$[4$ Marks$]$

iii. Give the other two acceptable ways in which the strain $0\mathrm{.}00045$ given in $($i$)$ above can be expressed.

$[4$ Marks$]$

$($b$)$ The force $P$ causes the beam in Fig. Q$2($b$)$ to rotate clockwise about pin A by angle of $0\mathrm{.}02$ degrees. Use the figure to:

i$.$ Find the displacement of point B and C$.[6$ Marks$]$

ii$.$ Finally, find the strains in wires $BD$ and $CE$

$[4$ Marks$]$