A steel bar of square cross-section (50 mm x 50 mm) and length 2 m elongates by 1 mm
due to axial pull of 10 kN. If the lateral strain is 0.0002 then the change in side of the bar
cross-section will be …
Answers
Answer:
0.0002feet the other person in this room is
solution :
let, A1 be the cross section of the steel bar before axial pull.
L1 be the length of the steel bar before axial pull.
A2 be the cross section of the steel bar after axial pull.
L2 be the length of the steel bar after axial pull.
V1 be volume of steel bar before axial pull.
V2 be volume of steel bar after axial pull.
here, A1 = 50mm*50mm = 100mm^2 = 100*10^-3m^2
L1 = 2m
force = 10kN
strain = 0.0002
volume of steel bar before axial pull.
V1 = L1*A1
V1 = 2*100*10^-3
V1 = 200*10^-3 m^3
now, strain = L2 - L1
L2 = strain + L1
L2 = 0.0002+2
L2 = 2.0002 m
as the volume will never be change before and after the axial pull
so, V2 = V1
L2*A2 = V1
A2 = V1/L2
A2 = 200*10^-3/ 2.0002
A2 = 0.0999 m^2
therefore, cross section of the steel bar after axial pull will be 0.0999 m^2