a) Tensile stress and strain

• define tensile stress

• the force applied to a material per its unit cross-sectional area

• state the formula for tensile stress

• σ = F/A

  • tensile stress (Pa) = force (N) / cross-sectional area (m²)

• define tensile strain

• the ratio of the extension to the original length of a material under tensile stress

• state the formula for tensile strain

• ε = x/L

  • tensile strain = extension (m) / original length (m)

• define ultimate tensile strength

• the maximum tensile stress that a material can withstand before breaking

• define young modulus

• the ratio of tensile stress to tensile strain of a material before the limit of proportionality

• → the stiffness of a material

• state the formula for young modulus

• E = σ/ε

  • young modulus (Pa) = tensile stress (Pa) / tensile strain

• state the factors that the young modulus of a material is not affected by

• anything other than the material of the object