The equation for net external force is the sum of all the external forces applied to the object. For example, a compilation of common external forces is friction force, normal force, air resistance, tension and applied force. Because these are vectors, adding them together produces the correct total external force.
Know MoreAlthough there are also internal forces acting on a body, these do not contribute to the total mechanical energy of a body when work is done on it, which is the quantity of greatest interest in calculations of external force. Work is the application of external force on a body to move it a certain distance.
Learn more about PhysicsWhen a force is applied to an object resting on a surface, a retarding force is that which opposes the force being applied to the object. A retarding force is usually that of friction, which must be overcome when moving an object resting on a surface. If the object is being moved upward along an inclined plane, gravity represents an additional force that must be overcome.
Full Answer >To calculate the normal force on an object, draw a free body diagram, determine the surface's angle, factor in the other present forces, and solve for the normal force. Note that the normal force is perpendicular to the surface the object sits on.
Full Answer >Weight is the measure of the gravitational force on an object. Weight is related to mass but is actually a separate property. Weight and mass are often treated as interchangeable because gravity on Earth does not vary much based on location.
Full Answer >The magnitude of the gravitational force acting on an object, F, is proportional to the universal gravitational constant, G, and the product of the two masses involved, m and M. It is inversely proportional to the distance between the objects, r, squared.
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