Interaction Forces and Weight

• Recall and apply Newton's third law.
• Recall ways in which objects interact, including by gravity, electrostatics, magnetism, and by contact (such as normal contact force and friction).
• Using examples of contact, magnetic, electrostatic and gravitational forces, describe how each involves a pair of objects interacting, with a force produced on each of the two objects.
• Represent interaction forces as vectors.
• Define weight and describe how it is measured.
• Recall and apply the relationship linking an object's weight to its mass and the gravitational field strength:

$W = m \times g$