Term
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Definition
| work is done when a force causes an object to move in the same direction that the force is applied |
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Term
| What is the formula for work? |
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Definition
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Term
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Definition
a force must be applied to an object (called "effort force" or "input force")
the object must move in the same direction as the force |
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Term
| If there is NO movement being done, is there any work being done? |
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Definition
NO!
**If an object doesn't move, then there is no work being done. |
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Term
| What is the purpose of a machine? |
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Definition
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Term
| How do machines make work easier? |
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Definition
- They can change the amount of force required
- They can change the distance the object has to move
- They can also change the direction
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Term
| Force and Distance have what kind of relationship? |
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Definition
Inverse relationship
*if you increase the force...you decrease the distance
*if you increase the distance... you decrease the force
*leave force and distance alone-but change the direction that the load moves (using gravity) |
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Term
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Definition
Work: Joules (J)
Force: Newtons (N)
Distance: meters (m) |
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Term
| Name the 4 types of simple machines |
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Definition
lever
pulley
wheel and axle
inclined plane |
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Term
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Definition
| a simple machine made with a rigid bar free to pivot (move) around a fixed point called a fulcrum |
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Term
| What are some examples of levers? |
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Definition
scissors
see-saw
crowbar
pliers
door
bottle opener
hockey stick
racket
shovel |
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Term
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Definition
| a simple machine made with rope, belt or chain wrapped around a grooved wheel |
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Term
| what are the two ways that a pulley works? |
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Definition
- it can change the direction of the force
- it can change the amount of force
two types of pulleys: Fixed Pulley and Moveable Pulley |
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Term
| What are examples of pulleys? |
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Definition
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Term
| What is a wheel and axle? |
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Definition
large wheel rigidly secured to smaller wheel, calle the axle
when one part turns, the other part turns too!
*If one part turns and the other one does not, it is not a true wheel and axle! |
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Term
| What are some examples of wheel and axles? |
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Definition
car tire
ferris wheel
pencil sharpener |
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Term
| What is an inclined plane? |
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Definition
a simple machine with no moving parts. It is simply a straight slanted surface
*it increases the distance traveled, but requires less force from you! |
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Term
| Name the two types of inclined planes and some examples |
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Definition
*Wedge: separating or holding device
ex: ax, ramp
Screw: circular inclined plane |
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Term
| What is mechanical advantage? |
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Definition
| The number of times a machine multiplies your effort force |
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Term
| WHat is the formula for mechanical advantage? |
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Definition
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