Question

A child causes a wagon to accelerate by pulling it with a horizontal force. newton's third law says that the wagon exerts an equal and opposite force on the child. how can the wagon accelerate? (hint: draw a free-body diagram for each object.)

Answer 1

Newton's first law of motion - sometimes referred to as the law of inertia. An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force. it is first law that describes the situation, there is force that is by pulling the wagon which results to the motion of the wagon

Answer 2

When the child applies force in the wagon, yes, the wagon also applies force in the hand of the child, but the wagon accelerates because it needs a lot of les force in order to accelerate, and the force that the wagon does in the hand of the child is not enough to make ani effect on the hand.

A similar example of this is: if you step in something with low friction near a wall, and you start to push the wall, you may see that the one moving now is you. This is because the force that you are applying in the wall is not enough to move the wall, but the force that the wall is returning to you is enough to move you.