A rectangular specimen is subjected to a three-point bending test. The specimen is 10 (l) centimeters long, 10 millimeters wide (b) and 10 millimeters height (h). The specimen is placed on two supports that are 5 cm apart (L), and the actuator is applying a force in the exact middle of the two supports (L/2). Immediately before failure, the testing machine records a force (F) of 50N, and a deformation (δ) of 2mm. We need to determine the maximum flexural strength (σ)