Consider uniaxial extension of a test specimen. It has gauge length L = 22 cm (the distance between where it is clamped in the testing fixture) with a cross section of diameter D = 1.8 mm. You expect the material to have a Young’s modulus E = 205 GPa and ultimate tensile strength of σu = 420 MPa. You would like to conduct a tensile test such that the test takes 2 minutes to go from initial loading to fracture. In completing the calculations below, assume the material’s stress-strain curve is perfectly linear until fracture.

Required:
a. At what force do you expect the specimen to fracture?
b. At what strain rate should you pull the specimen, in mm/minute? Assume the material undergoes brittle fracture and its stress-strain curve is perfectly linear to fracture.
c. What is the elongation (in inches) of the specimen in the moment just prior to fracture?