Introduction to Dynamics

Abstract

Keywords Acceleration – Distance and displacement – Dynamics – Inertia and momentum – Kinematics and kinetics – Linear, angular, and general motions – Reference frames and coordinate systems – Speed and velocity 6.1 Dynamics Dynamics is the study of bodies in motion. Dynamics is concerned with describing motion and explaining its causes. The general field of dynamics consists of two major areas: kinematics and kinetics. Each of these areas can be further divided to describe and explain linear, angular, or general motion of bodies. The fundamental concepts in dynamics are space (relative position or displacement), time, mass, and force. Other important concepts include velocity, acceleration, torque, moment, work, energy, power, impulse, and momentum. The broad definitions of basic terms and concepts in dynamics will be introduced in this chapter. The details of kinematic and kinetic characteristics of moving bodies will be covered in the following chapters. 6.2 Kinematics and Kinetics The field of kinematics is concerned with the description of geometric and time-dependent aspects of motion without dealing with the forces causing the motion. Kinematic analyses are based on the relationships between displacement, velocity, and acceleration vectors. These relationships appear in the form of differential and integral equations. The field of kinetics is based on kinematics, and it incorporates into the analyses the effects of forces and torques that cause the motion. Kinetic analyses utilize Newton's second law of motion that can take various mathematical forms. There are a number of different approaches to the solutions of problems in kinetics. These approaches are based on the equations of motion, work and energy methods, and impulse and momentum