Lecture
This lecture covers the concept of kinetic energy, including its various forms such as gravitational, electrical, and elastic potential energy. It explains how energy can transform between different forms, illustrated with examples like a simple pendulum and elastic collisions. The lecture also delves into the calculation of kinetic energy and the work done by external forces, emphasizing the conservation of energy principle. Through practical examples like a ball bouncing on the ground and objects sliding on surfaces, the instructor demonstrates how kinetic energy changes with respect to external forces and motion directions.