Answer:
0.0003758 m²
Explanation:
The formula to apply is;
ΔL=1/Y *F/A*L₀
Where ΔL=change in length = 0.412 in
Y=modulus of elasticity=30000000 psi
change psi to Pa
1 psi= 6.894757 kPa
30000000=?
6.894757 *30,000,000 =206842710000 Pa
F=applied force = 12000 lb---change to Newtons
1 lb=4.4482189159 N
12000 lb=? 12000*4.4482189159 =53378.6 N
A=cross-sectional area=?
L₀=original length of the rod= 50 ft ----change to meters
1ft =0.3048
50 ft=50*0.3048=15.24 m
ΔL =0.412 in -----change to meters
1 in =0.0254
0.412 in =? 0.412*0.0254 =0.0104648 m
Applying the formula
ΔL=1/Y *F/A*L₀
0.0104648 =1/206842710000 *(53378.6/A)*15.24
142031994.2=53378.6/A
A=53378.6/142031994.2
A=0.0003758 m²
