"Kinematics, as previously stated is the study of motion without consideration of the cause of that motion. As noted in Chapters 1 through 3, particles have no orientation in space, only position. In Chapter 4, systems of particles were examined, and, in general, each of the particles in a system was free to move independently. The principles of kinematics will now be applied to a system of particles that are rigidly connected, called a rigid body. The assumption that a body is rigid means that the deformation of objects are assumed to be negligible and that the distance between any two points on the body remains constant. the body may translate in a direction with components along the three coordinate axes and may rotate about any three axes." p300

DEGREES OF FREEDOM
THE NUMBER OF WAYS OR DIMENSIONS THAT A SYSTEM IS FREE (UNCONSTRAINED) TO MOVE

LINEAR
PROPERTY OF SYSTEMS WHERE THE SYSTEM OUTPUT OR RESPONSE IS IN DIRECT PROPORTION TO THE INPUT. DOUBLING THE INPUT (LOAD, FORCE, ENERGY, TENSION,...) HAS THE EFFECT OF DOUBLING THE OUTPUT (STRETCH, COMPRESSION, DISPLACEMENT,...)

RECTILINEAR/CURVILINEAR TRANSLATION
TRANSLATION IS A FORM OF NONROTATIONAL MOTION IN WHICH ALL PARTS OF A RIGID BODY EXPERIENCE THE SAME DISPLACEMENTS, VELOCITY, ACCELERATION AT THE SAME TIME. RECTILINEAR TRANSLATION IS TRANSLATIONAL MOTION ALONG A STRAIGHT LINE. CURVILINEAR TRANSLATION IS TRANSLATION MOVEMENT FOLLOWING A CURVE PATH.

RIGID BODY
AN OBJECT IN WHICH ALL THE COMPONENT PARTS REMAIN FIXED IN POSITION RELATIVE TO EACH OTHER.

RIGID BODY

SIX DEGREES OF FREEDOM

TRANSLATION