Problem $69)..$A closely coiled helical spring is to carry a load of $500$ N$.$ Its mean coil diameter is to be $10$ times that of the wire diameter. Calculate these diameters if the maximum shear stress in the material of the spring is to be $80$ N$/$mm $^2$

A closely coiled helical spring is to carry a load of $500$ N$.$ Its mean coil diameter is to be $10$ times that of the wire diameter. Calculate these diameters if the maximum shear stress in the material of the spring is to be $80$ N$/$mm $^2$