Interaction pair

Two forces arising from the same interaction: each object exerts a force on the other. They are equal in magnitude and opposite in direction.

When a table supports a book, the table pushes on the book and the book pushes on the table. These two forces form an interaction pair.

Identify an interaction pair by naming both objects: ‘force of A on B’ and ‘force of B on A’. The forces act on different objects.

Two forces arising from the same interaction: each object exerts a force on the other. They are equal in magnitude and opposite in direction.

When a table supports a book, the table pushes on the book and the book pushes on the table. These two forces form an interaction pair.

Identify an interaction pair by naming both objects: ‘force of A on B’ and ‘force of B on A’. The forces act on different objects.

Definition