Answer:
a)Percent reduction in area=54.23 %
b)Percent elongation=32.87 %
Step-by-step explanation:
Given that
Di= 11.53 mm
Df= 7.80 mm
Li= 51.4 mm
Lf= 68.3 mm
A= π/4 D²
a)
Percent reduction in area ,RA
![RA=(A_i-A_f)/(A_i)* 100](https://img.qammunity.org/2020/formulas/engineering/college/kdfxwzy97pv4aa3ab9zq3y3hsciizky1c9.png)
![RA=(D_i^2-D_f^2)/(D_i^2)* 100](https://img.qammunity.org/2020/formulas/engineering/college/pmfxohb7wngwlrf975mbarh34x8d9376ii.png)
![RA=(11.53^2-7.8^2)/(11.53^2)* 100](https://img.qammunity.org/2020/formulas/engineering/college/74q970e2kfn1vdv4hbjfktwdnfhggns9nw.png)
RA= 54.23 %
Percent reduction in area=54.23 %
b)
Percent elongation EL
![EL=(L_f-L_i)/(L_i)* 100](https://img.qammunity.org/2020/formulas/engineering/college/erwjrxdiv5hpoqi9nnggsr83ov1ucuk1mo.png)
![EL=(68.3-51.4)/(51.4)* 100](https://img.qammunity.org/2020/formulas/engineering/college/loqydm2vku8lvp5tkzwxjevq6exvzhypig.png)
EL=32.87 %
Percent elongation=32.87 %