A cable with a restrainer at the bottom hangs vertically from its upper end (see figure). The

Question:

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 = 40 mm2 and an effective modulus of elasticity E = 130 GPa. A slider of mass M = 35 kg drops from a height h = 1.0 m onto the restrainer.
If the allowable stress in the cable under an impact load is 500 MPa, what is the minimum permissible length L of the cable?