Which explanation describes the forces involved for a person to walk down the sidewalk?

Question

A.
The person's feet push backward on the sidewalk; the sidewalk pushes backward on the person.
B.
The person's feet push forward on the sidewalk; the sidewalk pushes forward on the person.
C.
The person's feet push forward on the sidewalk; the sidewalk does not push on the person.
D.
The person's feet push backward on the sidewalk; the sidewalk pushes forward on the person.

Answer 1

The correct explanation describing the forces involved for a person to walk down the sidewalk is:

A. The person's feet push backward on the sidewalk; the sidewalk pushes backward on the person.

This is in accordance with Newton's Third Law of Motion, which states that for every action, there is an equal and opposite reaction. The person pushes backward against the sidewalk, and in response, the sidewalk exerts an equal force forward on the person, propelling them forward as they walk.