| A | B |
|---|
| force | a push or pull that starts, stops, or changes the direction of an object-gives energy to an object |
| newton | SI unit for force |
| friction | occurs when the surfaces of any kind of matter move past each other-force that opposes motion |
| terminal velocity | the upward and downward forces are equal |
| projectile motion | combination of the downward force of gravity and the horizontal motion of velocity |
| inertia | the tendency of an object to resist any change in motion |
| momentum | inertia of motion(mass x velocity) |
| the law of the conservation of momentum | maintaining and transferring momentum |
| centripetal force | any force that causes an object to follow a circular path |
| Newton's third law of motion | when one object exerts a force upon a second object, the second object exerts an equal and opposite force upon the first object(every action there is an equal and opposite reaction) |
| universal forces | the four forces on Earth and the universe(gravitational, electromagnetic, strong nuclear force, and weak nuclear force |
| Newton's law of universal gravitation | every object in the universe attracts every other object |
| electromagnetic forces | two different forces(electric force and magnetic force) that attract or repel each other |
| electric force | exists between charged particles |
| magnetic force | force between two magnets |
| matter | made of tiny particles called atoms |
| atom | composed of electrons orbiting around a nucleus of protons and neutrons |
| nuclear forces | forces that hold the particles in the nucleus together |
| gravity | determines weight |
| Newton's first law of motion | an object at rest stays at rest and an object in motion stays in motion unless acted on by an outside force |
| types of friction | sliding, rolling, and fluid friction |
| Newton's second law of motion | states that force equals mass times acceleration |
| motion occurs | when forces on an object are unbalanced |
| gravitational force | the attraction between objects in the universe |
