Exercise E$6\mathrm{.}3$

The extension of the cable of a hoist was considered when lifting a mass of $250$ kg $.$ Find the stress in the cable of cross$-$sectional area $80$ mm $2,$ and evaluate the factor of safety between the applied stress and the yield stress, for steel $($yield stress $300$ MPa $)$ and polypropylene $($yield stress $32$ MPa $)?$ What mass would lead to failure in each material?

$m=250kg$

$==\frac{F}{A}$

$A=80m{m}^2$

yield stress steel $=300$mpa,$m_s=$

yield stress $pp=32$mPa,$m_{pp}=$