Comments: when, for example, L=10h and v=1/3 , this quotient is 1/125 the strain energy owing to the shear is less than 1 percent. For a slender beam, h≪L it is observsd that the energy is due mainly to bending. Therefore, it is usual to neglect the shear in evaluating the stain energy in beams of ordinary proportions. Unless stated otherwise, we adhere to this practice.