Question

The greatest length of the wire made of material of breaking stress $8\times {10}^{8}N/m^2$ and density $8\times {10}^{3}kg{m}^3$ that can be suspended from a rigid support without breaking is $(g=10m/s^2)$

• A. $1km$
• B. $0.1km$
• C. $10km$
• D. $20$

Answer 1

The correct option is C $10km$

$stress=length\times desity\times g$
$length=\frac{stress}{g\times density}$
$=\frac{8\times {10}^8}{10\times 8\times {10}^3}$

$=10km$