object A	object B	Type
Cup	Earth	gravitational
Cup	Table	electrostatic
Table	Earth	gravitational
Table	Earth	electrostatic

First, identify the interacting bodies, object A and object B. Secondly, identify the type of force. Then substitute into the following to identify the third law pairs: The object A exerts a(n) type force on the object B. The object B exerts a(n) type force on the object A. The forces are equal in magnitude and opposite in direction. Let us take the cup/Earth system as an example. "The cup exerts a gravitational force on the Earth. The Earth exerts a gravitational force on the cup. The forces are equal in magnitude and opposite in direction."

- In the same way as the example, above, work out the third law pairs for the other systems in the table.

- There is a third law pair not represented in the table. What is it, and why is it absent?