Question

Distinguish between kinematics and kinetics. Discuss how they differ and what they measure using sporting examples.

Answer 1

Kinematics is the branch of classical mechanics which describes the motion of points, bodies (objects) and systems of bodies (groups of objects) without consideration of the causes of motion. So you only have velocities and accelerations without the forces/torques which creates the motion. For example, take a body running with some constant velocity, for calculating the the velocity of body after some time, we use equation of motion. This defines kinematics.

Kinetics is a term for the branch of classical mechanics that is concerned with the relationship between the motion of bodies and its causes, namely forces and torques. So here you have both velocities, accelerations and the forces which creates the motion. For example, when a boy pushes a sphere of some mass, the forces and torque exerted by the boy is defined by the branch of kinetics.