The force of A on B is equal and opposite to the force of B on A

Forces are what make things go. This activity introduces the newton -- the unit for measurement of force -- and the force scale - the tool for measuring it.

Forces occur because things interact. When one object A is exerting a force on another object B, there is always an equal and opposite force of B on A.

Main pages in this section	Estimated time required
Force weighs in	30 minutes
The Law of Interaction	10 minutes
mass, weight, and density	20 minutes
Science content: Force	30 minutes
Discussion of the unit on force	15 minutes

Materials needed for this section

• Force scale*
• 2 Newton weight*
• rubber bands
• 1 box paper clips
• various objects to weigh
• magnets*

Supplementary material:
Why Study Forces?
Examples of the Law of Interaction
Massess of objects

Next section:Balanced forces