A sketch of the isolated body which shows only the forces acting upon the body.

Its physical meaning, as applied to a body, is that the body either is at rest or is moving in a straight line with constant velocity.

Those in which the lines of action neither are parallel nor intersect in a common point.

We consider the effects and distribution of forces on rigid bodies which are and remain at rest, or of having constant velocity.

The forces acting on the free body.

Considered in strength of materials.

The perpendicular distance from the moment center to the line of action of the force.

The effect of a system of forces on a body.

Have a size or magnitude only and need no other information to specify them.

The measure of its ability to produce turning or twisting about the axis.

Forces whose lines of action pass through a common point.

Those in which the lines of action are parallel.

Is the measure of the capacity or ability of the force to produce twisting or turning effect about an axis.

States that the external effect of a force on a body is the same for all points of application along its line of action.

States that the moment of a force about any point is equal to the algebraic sum of the moments of the component forces about the same point.

The process of adding vectors geometrically.

The product of the force and the perpendicular distance from the axis to the line of action of the force.

The term used to designate the condition where the resultant of a system of forces is zero.

Defined as a definite amount of matter the parts of which are fixed in position relative to each other.

The resultant of two forces is the diagonal of the parallelogram formed on the vectors of these forces.

Considered in engineering mechanics.

Defined as one which does not show the point of application of the vector.

To produce stress and deformation in the body on which the force acts.

When the lines of action of all the forces in a force system line in one plane.

Defined as the science which considers the effects of forces on rigid bodies.

It is independent of the point of application.

Forces acting at some angle from the coordinate axes can be resolved into mutually perpendicular forces.

Is any arrangement where two or more forces act on a body or on a group or related bodies.

Is a force or a couple that will have the same effect to the body, both in translation and rotation, if all the forces are removed and replaced by the resultant.

The principles of mechanics are postulated upon several self-evident facts which cannot be proved mathematically but can only be demonstrated to be true.

States that when two vectors are represented as two sides of the triangle with the order of magnitude and direction, then the third side of the triangle represents the magnitude and direction of the resultant vector.

Defined as that which changes, or tends to change, the state of motion of a body.

The intersection of the plane and the axis.

The axis of moments, which is perpendicular to the plane of the forces, appears as a point.

Have both a size or magnitude and a direction, called the line of action of the quantity.

Two forces are in equilibrium only when equal in magnitude, opposite in direction, and collinear in action.

This law says, "Two vectors can be arranged as adjacent sides of a parallelogram such that their tails attach with each other and the sum of the two vectors is equal to the diagonal of the parallelogram whose tail is the same as the two vectors".

We consider the motion of rigid bodies caused by the forces acting upon them.

An isolated view of a body which shows only the external forces exerted on the body.