The document discusses the simple machine known as the screw. It explains that a screw is a long post wrapped with metal threads, and is a type of inclined plane wrapped around a cylinder. Screws help hold things together and make work easier to do by providing an inclined surface that reduces the amount of force needed, though more turns may be required with screws that have threads close together versus those with threads farther apart.

1. Simple Machines: The Screw
There are six simple machines. They
make it easier for us to do work.

2. Simple Machines: The Screw

3. Simple Machines: The Screw
The screw is one kind of simple
machine. Screws help us hold things
together.

4. Simple Machines: The Screw
A screw is a long post that is wrapped
with metal threads. A screw is actually a
kind of inclined plane.

5. Simple Machines: The Screw
It is an inclined plane that is wrapped
around a cylinder.

6. Simple Machines: The Screw
If you follow the threads on a
screw, they will form a long ramp from
the bottom of the screw to the top of
the screw.

7. Simple Machines: The Screw
The threads on the screw may be close
together. The threads may be farther
apart.

8. Simple Machines: The Screw
A screw with threads that are close
together makes work easy to do. It
forms a long inclined plane.

9. Simple Machines: The Screw
The work is easy to do, but you will have
to turn the screw many times.

10. Simple Machines: The Screw
A screw with threads that are farther
apart forms a shorter inclined plane.

11. Simple Machines: The Screw
The work is harder to do, but you will not
have to turn the screw as many times.

12. Simple Machines: The Screw
Skill Assessment