usings youngs modulus, i need to figure out the extension in a cable...now

m = 950kg

youngs modulus of steel = 210 GN m^-2

diameter = 11.5929mm

so where am i going wrong?

f = m x g

f = 950mg x 210GNM^-2

f = 1.995 x 10^14 kg m^-2

f = 1.995 N

stress (as i dont have a sigma symbol, ill use 's')

s = f / a

s = 1.995 N / 11.5929mm

s = 0.1720

extension = s x original length

e = 0.1720 x 8

e = 1.376mm

Thanks Guys