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Quinn science M1
Matter in Motion
| Question | Answer |
|---|---|
| motion | an object's change in position over time when compared to a reference point |
| speed | the rate at which an object moves, depends on the distance traveled and the time it takes to travel that distance, = d/t |
| velocity | speed in a particular direction |
| acceleration | the rate at which velocity changes, speed, direction or both change |
| force | a push or pull, has size and direction |
| newton | the SI unit of force |
| net force | the forces that results from combining all the forces exerted on an object |
| friction | a force that opposes motion between two surfaces that are touching |
| gravity | a force of attraction between objects due to their masses and distance between them |
| weight | a measure of the gravitational force exerted on an object, usually the Earth |
| mass | the amount of matter that something is made of |
| reference point | an object that appears to stay in place in relation to an object being observed for motion |
| average speed | the overall rate at which an object moves, total distance divided by total time |
| resultant velocity | the combination of two or more velocities |
| deceleration | negative acceleration, velocity decreases |
| centripetal acceleration | the acceleration that occurs in a circular motion, constantly changes direction, acceleration occurs continuously |
| balanced forces | net force is zero, no motion or acceleration |
| unbalanced forces | net force is NOT zero, there is motion or acceleration |
| sliding friction | direct contact of two surfaces |
| rolling friction | use of wheels to reduce the amount of friction |
| fluid friction | friction between an object and a liquid or gas |
| static friction | disappears as soon as an object starts to move |
| lubricant | a substance applied to surfaces to reduce friction between them |
| reduce friction | lubricants, smoother surfaces, and use of wheels |
| increase friction | rough surface, more force |
| law of universal gravitation | all objects attract each other, depends on mass and distance between two objects |
| more gravitational pull | more mass and less distance |