A light fitting of mass 54 kg is suspended from a copper wire 4 mm in diameter. (UTS=415 MPa and E = 112000 MPa) Calculate the stress in the wire. Calculate the factor of safety.

Respuesta :

Answer:

42.17 MPa,  9.83

Explanation:

We have given mass m=54 kg

Diameter d =4 mm so radius [tex]r=\frac{d}{2}=\frac{4}{2}=2 mm=2\times 10^{-3}m[/tex]

UTS = 415 MPa

E =112000

Weight = mg =54×9.81=529.74 N

Area [tex]A=\pi r^2=3.14\times (2\times 10^{-3})^2=12.56\times 10^{-6}m^2[/tex]

We know that [tex]stress=\frac{load}{area }=\frac{529.74}{12.56\times 10^{-6}}=42.176\times 10^6\ N/m^2=42.176MPa[/tex]

[tex]factor\ of\ safety=\frac{UTS}{stress}=\frac{415}{42.17}=9.83[/tex]