Answer:
Explanation: Force = mg as the wire is fixed at one point and the load is inserted at one end.
g=9.8m/s²
F= mg
F= 20×9.8= 19.6 newton
Strain= Δl/L
where Δl= change in length
and L= original length
Strain = 0.24×0.001 m/4m
Strain=0.00006
Stress= F/A
where A = cross sectional area
therefore A = π× (diametre/2)²
A=3.14×1²≈3.14 mm²= 0.000000314m²
Stress = 19.6/0.000000314=62420382 Pascal