physics please?

Question

I need help pleaseeeeee?
hey everyone i need help last question

8) Christine hangs a 3.0 m length of steel wire from the
ceiling and attaches a mass of 2.0 kg to the end of this
wire. She observes that the mass extends the length of
the wire by 3.6 mm. If the diameter of the wire is
0.32 mm, calculate:
a) the strain of the wire

b) the stress on the wire

c) a value of Young’s modulus for the steel.

Answer 1

Stress= F/A
Strain = extension/ length

YM=Stress/Strain




a) Stress= F/A= mg/(pi D^2 /4)=
Stress=4 x 2.0 x 9.81/ (3.14159 x (.00032)^2)
Stress=243.955 E+6 N/m^2

b)Strain = extension/ length
Strain = .0034m / 3.0 m=
Strain =0.00113=1.13E-3


c) YM=Stress/Strain
YM=215.9 E+9 N/m^2