Question

A steel wire having a radius of $2.0 \, mm$, carrying a load of $4 \, kg$, is hanging from a ceiling. Given that $g =3.1 \pi \, ms ^{-2}$, what will be the tensile stress (in $Nm ^{-2}$ ) that would be developed in the wire?
$\left(3.1 \times 10^6\right)$

Answer 1

$\left(3.1 \times 10^6\right)$ Given,
Radius of wire, $r=2 \,mm$
Mass of the load $m =4\, kg$
$\text { Stress }=\frac{F}{A}=\frac{m g}{\pi(r)^2}$
$=\frac{4 \times 3.1 \pi}{\pi \times\left(2 \times 10^{-3}\right)^2}=3.1 \times 10^6\, N / m ^2$