Answer :

Answer: The action-reaction pair in a person taking a step involves the foot exerting force on the ground (action) and the ground exerting an equal and opposite force on the foot (reaction).

Explanation: When a person takes a step, the action-reaction pair can be described by Newton's third law of motion. The foot pushes the ground backwards (action) and in response, the ground pushes the foot forward (reaction). This reaction force propels the person forward, allowing them to walk or run.

Or in simpler terms, the action is the foot exerting a downwards and backwards force on the ground and the reaction is the ground exerting an equal and opposite upwards and forward force on the foot.