Dynamics

Dynamics is the study of objects in motion and the forces acting on them. It sits alongside statics as one of the two halves of engineering mechanics: statics analyzes bodies in equilibrium, where forces balance and nothing accelerates, while dynamics takes over the moment acceleration appears.

Dynamics itself splits into two parts. Kinematics describes motion without asking why it happens — position, velocity, and acceleration as functions of time, for particles and rigid bodies alike. Kinetics supplies the why, connecting forces to motion through Newton's second law, F = ma. From that foundation, engineers derive the workhorse methods of the field: work-energy principles, impulse and momentum, and the rotational analogs relating torque, moment of inertia, and angular acceleration.

Mastery of dynamics is what lets engineers predict how systems behave: the stopping distance of a vehicle, the forces in a machine linkage, vibration in a rotating shaft, or the trajectory of a projectile. Problems typically start with a free-body diagram, apply Newton's laws or an energy/momentum method, and solve for the unknown motion or force.

Dynamics is a dedicated exam topic on the FE Civil exam, covering particle and rigid-body kinematics and kinetics, work-energy, and impulse-momentum methods. The AP Physics 1 exam builds the same foundation — Newton's laws, forces, and motion, extending into oscillations — so a solid grasp of dynamics pays off across both engineering licensure and physics coursework.