| A | B |
|---|
| Newton | Unit of force; 1 N is the amount of force required to accelerate 1 kg at 1 meter per second squared. |
| force | an action exerted on an object which may change the object's state of motion |
| contact force | a force that results from physical contact |
| field force | forces that do not involve physical contact |
| free body diagram | diagram that shows the directions and magnitudes of the forces that act on an object |
| inertia | the tendency of an object to resist changes in its state of motion |
| net force | the vector sum of all the forces |
| mass | a measure of the inertia of an object; the amount of matter |
| equilibrium | the state of being at rest or moving at a constant velocity; net force is equal to zero |
| Newton's 1st Law | Objects at rest tend to stay at rest; objects in motion tend to stay in motion unless acted on by an unbalanced force. |
| Newton's 2nd Law | The net force on an object is equal to the product of its mass and its acceleration. |
| Newton's 3rd Law | For every force that acts on an object, there is an equal and opposite force that the object exerts. |
| normal force | The force of a surface on an object which is always perpendicular to the surface. |
| tension | The force within a string or rope. |
| weight | The force of gravity. |
| friction | A force caused by one surface sliding, or attempting to slide, over another. |
| coefficient of friction | The ratio of the friction force to the normal force. |
| static friction | A force caused by one object attempting to slide over another, which opposes the attempt. |
| kinetic friction | A force caused by one object sliding over another which opposes the motion. |
