exerted by two objects on each other are often called an action- reaction force pair. Either force can be considered the action force or the reaction force. However, action and reaction force pairs don’t cancel because they act on different objects. Forces can cancel only if they act on the same object.

There are two forces resulting from this interaction – a force on the chair and a force on your body. These two forces are called action and reaction forces and are the subject of Newton’s third law of motion. Formally stated, Newton’s third law is: For every action, there is an equal and opposite reaction.

Balanced forces do not change the motion of an object. An object that is sitting still will stay still if the forces acting on it are balanced. If an object is in motion, it will keep moving in the same direction and at the same speed if the forces acting on it are balanced.

Objects can’t physically move left and right, simultaneously. After a period of time, we can say it moved x meters left or right, x meters forward or backwards, and, x meters up or down. The sum total, is the direction. But at the same time the same object also can move to all the directions.

Force is defined as a push or pull on an object. Forces affect how objects move. They may cause motion; they may also slow, stop, or change the direction of motion of an object that is already moving. Since force cause changes in the speed or direction of an object, we can say that forces cause changes in velocity.

Newton’s first law of motion state that an object will not experience a change in motion unless acted upon by a(n) BALANCED force. Resistance to change in motion is called STASIS. False (INERTIA) Action and reaction forces acting in opposite direction DO cancel out because they act on different objects.

A force is a push or pull that causes an object to move, change direction, change speed, or stop. Without a force, an object that is moving will continue to move and an object at rest will remain at rest. Not all forces cause motion, however. Some forces, like gravity and friction, resist or work against movement.

Question: What are five ways a force can change motion? Answer: The action by a force can cause an object to move or speed up , to slow down , to stop, or to change direction.

Engineers determine the loads or external forces that act upon a structure. When external forces are applied to a structure, internal stresses (internal forces) develop resistance to the outside forces. The opposition of external and internal forces is what holds the structure together.

When a beam or frame is subjected to transverse loadings, the three possible internal forces that are developed are the normal or axial force, the shearing force, and the bending moment, as shown in section k of the cantilever of Figure 4.1.

For our purposes, we will simply say that external forces include the applied force, normal force, tension force, friction force, and air resistance force. And for our purposes, the internal forces include the gravity forces, magnetic force, electrical force, and spring force.