Find the greatest length of the wire made of material of breaking stress `8 xx 10^8Nm^(-2)` and density `8xx10^3 kgm^(-3)` that can be suspended from a rigid support without breaking.

Explanation

Greatest length of the wire without breaking.
L = Braking Stress / `rho g`
Here, breaking stress ` = 8 xx 10^8 Nm^(-2)`
` rho = 8 xx 10^3 kg m^(-3) , g = 10 ms^(-2)`
`L = (8 xx 10^8)/(8 xx 10^3 xx 10) = 1 xx 10^4 m = 10 km`