| A | B |
|---|
| force | a push or pull that acts on an object |
| net force | the overall force acting on an object after all the forces are combined |
| friction | a force that opposes the motion of objects as they move past each other |
| static friction | the friction of force that acts on objects that are not moving |
| sliding friction | a force that opposes the direction of motion of an object as it slides over a surface |
| rolling friction | the friction force that acts on rolling objects |
| fluid friction | frictional force that opposes the motion of an object through a fluid |
| air resistance | fluid friction acting on an object moving through the air |
| gravity | a force that acts between any two masses |
| terminal velocity | the constant velocity of a falling object when the force of air resistance equals the force of gravity |
| projectile motion | the motion of a falling object after it is given an initial forward velocity |
| inertia | the tendency of an object to resist a change in its motion |
| mass | a measure of the inertia of an obect and depends on the amount of matter the object contains |
| weight | the force of gravity acting on an object |
| Newton's First Law of Motion | An object at rest stays at rest, an object in motion stays in motion unless an outside force acts upon it |
| Newton's Second Law of Motion | the acceleration of an object is equal to the net force acting on it divided by the object's mass |
| Newton's Third Law of Motion | when one object exerts a force on a second object the second object exerts an equal an opposite force on the first |
| momentum | product of an object's mass and velocity |
| law of conservation of momentum | if no net force acts on a system, then the total momentum of the system does not change |
| electromagnetic force | associated with charged particles |
| strong nuclear force | a powerful force of attraction that acts only on the neutrons and protons in the nucleus to hold them together |
| gravitational force | an attractive froce that acts between any two masses |
| weak nuclear force | an attractive force that acts only over a short range |
| centripetal force | a center directed force that continuously changes the direction of an object to make it move in a circle |
