A steel wire 2.7-mm in diameter stretches by 0.211 percent when a mass is suspended from it. How large is the mass in kg?

1 answer

wondering what temperature this occurs at.

dl/l=(force/area)/young's modulus

force=mass*g=youngMod*area*dl/l
dl/l= .0211
area=PI(.0027/2)^2
g= 9.8N/kg
mass(in kg)=youngMod*area*dl/l*1/9.8

Young mod is about 200E9 N/m^2 about, but it depends on temperature.