This document contains a presentation on engineering mechanics and friction. It defines friction as the force between two surfaces that are sliding or trying to slide across one another. It describes the different types of friction including static and kinetic friction. Several example problems are provided to demonstrate how to calculate static and kinetic friction forces and determine if blocks will start to move on inclined planes. The key factors that determine friction like normal force, surface roughness, and coefficients of static and kinetic friction are discussed.