Stress-strain curves show how real materials respond to forces that are applied to them. Materials such as steel have a region of elasticity where they approximate an ideal spring and a region where they start to deform plastically. Where the materials are acting like an ideal spring, how do we find their Young's modulus?

W) It is the slope of the stress-strain curve

X) It is the integral of the curve in the elastic region

Y) It is the \(y\)-intercept of the stress-strain curve

Z) It is the second derivative of the curve just after transition into the region of plastic deformation
W) IT IS THE SLOPE OF THE STRESS-STRAIN CURVE