Answer:
a. ε = 0.225 , % = 22.56 %
b. ε = 0.1128 , % = 11.28 %
Explanation:
E = 24.0 Mpa
m = 76.0 kg
d = 11.0 cm ² * = 1.1 x 10⁻³ m
a.
Use the equation ti determine the force and stress replacing and solve to ε'
E = σ / ε ⇒ ε = σ / E
σ is the relation between the force in determine area and know the force is mass by gravity
F/A / E ⇒ mg / EA
ε = [ 8 * 76.0kg * 9.8m/s² ] / (24.0x 10⁶ Pa * 1.1 x 10 ⁻³ m²)
ε = 0.225
Now the
% 0.205 * 100 = 22.57 %
b.
ε = [ 4 * 76.0kg * 9.8m/s² ] / (24.0x 10⁶ Pa * 1.1 x 10 ⁻³ m²)
ε = 0.1128
% 0.1128 * 100 = 11.28 %
Notice is the half of the porcent