1. Kinetic energy is the energy of motion. It is defined using an object's mass and velocity according to the formula: Kinetic Energy (EK) = 1/2 * mass * velocity^2.
2. Work is defined as the transfer of kinetic energy due to a force acting over a distance. The work-kinetic energy theorem states that work done on an object equals its change in kinetic energy.
3. Applying Newton's second law and the work-kinetic energy theorem allows calculating the work done on an object from its change in velocity, proving the relationship between work and change in kinetic energy.