Question

Find the greatest length of steel wire that can hang vertically without breaking. Breaking stress of steel = 8.0 x 10⁸ N/m². Density of steel = 8.0 x 10³ kg/m³. Take g = 10 m/s².

Answer 1

Let l be the length of the wire that can hang vertically without breaking. Then the stretching force on it is equal to its own weight. If therefore, A is the area of cross-section and p the density, then