Unbalanced forces that have a net force in a certain direction are what lead to changes in motion. When multiple forces act on a body, the resultant force, calculated as the vectorial sum of the individual forces, determines whether the body moves or not.Know More
When this resultant force is equal to zero, the individual forces that contribute to this resultant force are balanced, and no motion results. If the resultant force equals any quantity other than zero, the forces that contribute to the resultant are unbalanced, and the body moves. Bodies being acted upon by balanced forces are said to be in equilibrium.
To measure the total forces acting on a body and determine resulting movements, free-body diagrams are constructed depicting the magnitude and direction of each force. Reaction forces resulting from the contact of the body with another body must be taken into account. A simple free-body diagram of an upright person shows the person's weight as a downward force and the upward reaction from the floor as an equal and opposite force. The person is in equilibrium because these two forces balance out. The reaction force from quicksand does not balance out with the weight of a person sinking in it, causing net downward motion.Learn more about Motion & Mechanics
According to Isaac Newton's second law of motion, acceleration is produced when a net force acts on a mass. The net force is the sum of all the forces acting on the mass.Full Answer >
Inertia is the quality a mass, or any object, has that keeps it still, if it is not moving, or in motion, if it is in motion. The relationship between mass and inertia has much to do with the first two laws of physics by Isaac Newton, which are that an object at rest will tend to stay at rest and an object in motion will tend to stay in motion.Full Answer >
Resistance to change in motion is called inertia. The amount of inertia in an object is directly proportional to its mass; an object with greater mass has more inertia than an object with less mass.Full Answer >
Energy of motion is the energy an object possesses due to its motion, which is also called kinetic energy. This means that the object, which has energy of motion, can do work on any object it hits.Full Answer >