Statics - Mechanics for Engineers Exam Graded to Pass!!!

Theoretical mechanics - The science which treats of the general laws of motion and equilibrium of material bodies and of their resulting mutual interactions. The branches of Mechanics - Mechanics is divided into statics, kinematics, and dynamics. The Subject of Statics - The branch of mechanics which studies the laws of composition of forces and the conditions of equilibrium of material bodies under the action of forces. First Principle of Statics - A free rigid body subjected to the action at two forces can be in equilibrium if, and only if, the two forces are equal in magnitude (F1=F2), collinear, and opposite in direction Second Principle of Statics - The action of a given force system on a rigid body remains unchanged If another balanced force system is added to, or subtracted from, the original system. Corollary of the 1st and 2 nd Principles. - The point of application of a force acting on a rigid body can be transferred to any other point on line of action of the force without altering its effect. 3 rd principle of the statics (Parallelogram Law) - Two forces applied at one point of a body have as their resultant a force applied at the same point and represented by the diagonal of a parallelogram constructed with the two given forces as its sides. 4th principle of statics (Newton's 3rd law) - To any action of one material body on another there is always an equal and opposite reaction. 5th principle of statics (Principle of Solidification) - If a freely deformable body subjected to the action of a force system is in equilibrium, the state of equilibrium will not be disturbed if the body solidifies (becomes rigid). Constraint body - A body whose displacement in space is restricted by other bodies, either connected to or in contact with it. Smooth. Plane (Surface) or Support. - A smooth surface is one whose friction can be neglected in the first approximation. Therefore, the reaction N of a smooth surface or support is directed normal to both contacting surfaces at their point of contact and is applied at that point. Direction of tension force - The reaction T of the string is thus directed along the string towards the point of suspension Cylindrical Pin (Bearing) - When two bodies are joined by means of a pin passing through holes in them the connection is called a joint or hinge. In this case neither the magnitude R nor the direction (angle a) of force R are immediately apparent. Ba1l-and-Socket Joint and Step Bearing - This type of constraint prevents displacement in any direction. The reaction R of a ball-and-socket joint or a pivot can have any direction in space. Neither its magnitude R nor Its angles with the x, y, and z axes are immediately apparent.