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Vocab unit 4
Science
| Term | Definition |
|---|---|
| Speed | Movement from place to another over time ; distance divided by time |
| Average | Time it takes to travel the whole distance |
| Instatntateus speed | Speed at an instant of time |
| Velocity | Speed of an object and it's direction of motion |
| Acceleration | Change in velocity divided by the amount of time needed for the change to occur |
| Force | A push or a pull |
| Newton's first law | Object at rest or in motion remains unless acted upon by another force |
| Newton's second law | The speed of an object (acceleration is directly proportional to the force acting on it |
| Newton's third law | When a force is exerted on an object , the object exerts an equal and opposite force on the first |
| Friction | Force that racist motion between two touching surfaces and always acts opposite to the direction of motion |
| Inertia | Tendency to resist in motion |
| Mass | The amount of matter in an object |
| Work | Applied forces causing an object to move in the direction of the force |
| Machine | A device with moving parts that works together to accomplish a task |
| Pulley | A object like a grooved wheel with a rope running thru the groove bad changes the direction of the input force |
| Lever | A stiff structure that rotates around a fixed point called fulcrum |
| Inclined plains | A sloped surface |
| Wedge | Moving of an inclined plane |
| Screw | The threads of screw are one long , continuos inclined plane ( wedge) and changes the direction of force |
| Simple machine | Uses only one movement |
| Compound machine | A combination of simple machines |
| Mechanical advantages | The ratio of an output to input force |