The gears of a wall clock. An electric motor (now removed) turned one gear very rapidly, It turned another, which turned another, which eventually made the hands go around.

Main pages in this section	Estimated time required
Levers	30 minutes
Pulleys	30 minutes
Science content: Simple Machines	30 minutes
Discussion of the unit on Simple Machines	30 minutes

Materials needed for this section

• Force scale*
• Ramp*
• Measuring Stick
• Graph paper (see advice on graphing)

Supplementary material: Why study simple machines?
More about simple machines

Next section:Floating and fluids