Engineering Mechanics Basics

Branches of Mechanics

• The branch of mechanics that deals with the behavior of solids under the application of forces when they are at rest or in motion is called Statics and Dynamics.
• Statics is the branch of mechanics that deals with the study of rigid bodies when they are at rest.
• Kinematics is the branch of mechanics that describes the motion of points, objects, and groups of objects without considering the forces that cause the motion.
• Dynamics is the branch of mechanics that specifically deals with the behavior of solids under the application of forces when they are in motion.

Rigid Bodies

• A rigid body is a body that does not alter its shape, size, or the distance between any two points on the body on the application of external forces.

Law of Transmissibility of Force

• According to the law of transmissibility of force, a force acting at a given point of a rigid body can be replaced by another force if the line of action of the two forces is the same.
• The limitations of the law of transmissibility of forces for rigid bodies are that it does not apply to non-rigid bodies or bodies that change shape under the application of forces.

Principle of Superposition of Force Systems

• The principle of superposition of force systems states that the combined effect of forces on a body is the vector sum of the individual forces.

Force and Resultant Force

• In the equation R = F1 + F2 + F3, 'R' represents the resultant force.
• For a force acting at a given point to be replaced by another force, the line of action of the two forces must be the same.