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lesson 3:3
lesson
| Question | Answer |
|---|---|
| there area total of three types of simple machines. | false |
| a lever consists of a bar that pivots about a fixed point called the focus. | false |
| a wedge is a sloped surface that forces materials apart. | true |
| which factors determine whether a lever is a first- class lever, second-class lever, or third-class lever? | input force, output force, fulcrum |
| what is a compound machine? | two or more simple machines that operate together and form a compound machine. |
| how do you calculate the overall efficiency of a compound machine? | multiply the efficiencies of each simple machine together. |
| an example of a wedge | your front teeth |
| an example of a screw | bottle caps |
| an example of an inclined plane | ramp |
| flag pole | pulley |
| wedge that splits wood | wedge |
| roller skates | wheel and axle |
| a lever's pivot point | fulcrum |
| a shaft that turns | axle |
| a wheelbarrow | second-class lever |
| what is a compound machine? | when two or more simple machines that operate together to form a compound machine. |
| how is the efficiency of a compound machine calculated? | by multiplying the efficiencies of each simple machine. |
| what happens to the efficiency of the overall machine as more simple machines are added to it? | each simple machine decreases the overall efficiency. |