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Unit #7 Hot Cards
Physics
| Question | Answer |
|---|---|
| An action that makes an object either move or change shape. (EX: a push, a pull, a twist.) | Force |
| The sum of all forces acting on an object | Net Force |
| A force that changes an object's motion or causes it to accelerate. | Unbalanced Force |
| Forces that are equal & acting in opposite directions. Since the net force is zero, NO MOVEMENT OCCURS! | Balanced Force |
| The transfer of energy as the result of motion. | Work |
| (Note: Work is measured in Joules, Forces in Networks & Distance in Meters!) - This means that something has to MOVE in order for "work" to be done. | Work = Force x Distance |
| Change's the amount and/or direction of the force that must be exerted to for work. You get the same work done with less force- thus it INCREASE EFFICIENCY! | Machine |
| A machine that consists of only one part | Simple Machine |
| A bar that is free to pivot about a fixed point called a fulcrum. The longer the effort arm the less required to move an object. (EX: hammer, seesaw, wheelbarrow.) | Lever |
| A slanted surface used to raise objects. It decreases the force required to raise an object by increasing the distance. (EX: a loading ramp.) | Inclined Plane |
| An arrangement of one or more wheels & rope (EX: the string on the flag pole.) | Pulley |
| A pulley that stays in place & turns as the cord moves over it. This pulley only gives a directional advantage- in other words, it only changes the direction of the force. it does NOT change the amount of the force or the distance. | Fixed Pulley |
| A pulley that is able to move with the load being raised. This pulley gives a mechanical advantage- in other words, it decreases the force by increasing the distance. (EX: amount of rope you pull!) | Moveable Pulley |