Lecture
This lecture covers the normal stresses in beams during bending, including the concept of a neutral axis, calculation of normal stresses, and determination of the second moment of area for simple and complex shapes. The lecture progresses from discussing the assumptions made for shear loading to deriving the flexure formula and exploring the second moment of area. Examples are provided to illustrate the calculation of the second moment of area and centroid for different cross-sections, emphasizing the importance of understanding the distribution of stresses in beams.