03-08-2012, 01:59 PM
COPLANAR FORCES
COPLANAR FORCES.pptx (Size: 170.58 KB / Downloads: 35)
Introduction
Forces that act in a single plane; thus the forces are parallel to the plane and their points of application are in the plane
Mechanism of inertial force:
In 3D space system, a force is recognized only by its inertial action. Inertial action is an action that
produces the phenomenon of inertia. Displacements of matter particles in space are necessary to create
inertial actions. Inertial forces are applied from outside a body. Inertial force is a force that invokes the
property of inertia about a matter body.
Equilibrium
Newton’s First Law - If, and only if, an object’s “mass center” has zero acceleration, then the sum of ALL of the forces acting on the object (body) is zero.
Where is a body’s mass center? We’ll study that in Module 4. But in this class, the entire body is at rest, so we know that the mass center, wherever it is, has zero acceleration.
Independent Equations
In a given problem, we can find only as many unknowns as we have independent equations.
For a system of coplanar, concurrent forces, Newton’s First Law yields only two independent equations for a given FBD.