Lecture
This lecture introduces two types of friction: solid friction in fluids (liquids or gases) and friction between rigid objects. The instructor explains the distinction between resistance to movement at low and high speeds, covering static and kinetic friction. The lecture delves into the calculation of generalized forces in non-conservative systems, using examples like ballistics with friction. Various experiments are conducted to demonstrate the concepts, including the influence of surface contact, viscosity, and shape on friction. The instructor also explores the difference between static and kinetic friction through practical demonstrations, highlighting the importance of surface contact and the adaptation of friction forces to external forces.