Posterous theme by Cory Watilo

Simple Screws

3rd graders learned that a screw is actually an inclined plane wrapped around a shaft.  Student used a screw driver to screw two different screws into a piece of wood.  Ask your student what the difference is between a coarse thread screw and a fine thread screw.  Which one has a longer inclined plane wrapped around it?  Which one should require less effort to screw in?

Picture_8