Problem $3(20$ points$)$

Consider your cellphone dangling from its earbuds cable. Answer the following question:

a$)$ What is your estimation for the following measurements?

$-$ The weight of the cellphone:

rams

$-$ The diameter of the copper wire inside the cable:

mm

$-$ The external diameter of the plastic insulation:

mm

$-$ The length of the cable $.$

Use these estimated values in part b$.$

Copper wire conductor

b$)$ Considering the weight of the cellphone is carried by the copper wire and the insulation together:

$-$ Determine the internal forces in copper wire and plastic insulation.

Your solution must include an FBD$.$ Hint: Ask yourself if the problem is statically determinate or indeterminate.

$-$ Determine the stress developed in the copper wire and the plastic insulation due to the weight of the cellphone.

$-$ By how much will the cable stretch? $\backslash (\backslash$left$($E$\_\{$p i$\}=2\mathrm{.}9\backslash$mathrm$\{$GPa$\},$ E$\_\{\backslash$text $\{$copper $\}\}=103\backslash$mathrm$\{$GPa$\}\backslash$right$)\backslash )$