A uniform cylindrical rod of cross-sectional area S is placed on a frictionless horizontal surface. Two equal and opposite forces, each of magnitude F , are applied outwardly along the length of the rod at its two ends. The tensile stress produced in the rod is:

Step-by-step solution

Consider a cross-section of the rod at any point along its length. Since the rod is in equilibrium under the action of two equal and opposite forces F at its ends, the net force on any part of the rod is zero. The internal restoring force (tension) T developed at any cross-section must balance the external force F applied at the ends. Thus, T = F . Tensile stress is defined as the internal restoring force per unit cross-sectional area. Tensile stress = T S = F S . Answer: F S