$2\mathrm{.}8-8$ A cable with a restrainer at the bottom hangs

vertically from its upper end $($see figure$).$ The cable has

an effective cross$-$sectional area $A=40m{m}^2$ and an

effective modulus of elasticity $E=130$GPa. A slider

of mass $M=35kg$ drops from a height $h=1\mathrm{.}0m$

onto the restrainer.

If the allowable stress in the cable under an

impact load is $500$MPa, what is the minimum per$-$

missible length $L$ of the cable?

PROBLEMS $2\mathrm{.}8-8$ and $2\mathrm{.}8-9$