Calculate the modulus of resilience (in N/mm2) for a 2 m long bar that stretches 2 mm under a limiting elastic axial load corresponding to a proof stress of 200 N/mm2.

A helical spring has a stiffness of 12 kN/m with 20 turns. If it is cut into two equal parts of 10 turns each and then connected in series, the stiffness of the resulting spring combination is:

A circular shaft is subjected to a bending moment of 600 N·m and a torque of 800 N·m. Its equivalent bending moment is: