Why Does the Wagon Still Accelerate?

Question:

If a horse exerts 500 N of force on a heavy wagon and the wagon pulls back on the horse with an equal force, why does the wagon still accelerate?

Answer:

The wagon still accelerates because the forces exerted by the horse and the wagon on each other do not cancel out, as they act on different bodies.

Final answer: The wagon still accelerates because the forces exerted by the horse and the wagon on each other do not cancel out, as they act on different bodies. The unbalanced force applied by the horse on the wagon results in the wagon's acceleration. This demonstrates Newton's Third Law that action and reaction forces don't cancel each other out because they act on different bodies.

Explanation:

The correct answer to why the wagon still accelerates even though the horse and wagon exert equal but opposite forces on each other is option B: 'Nevertheless, there is still an unbalanced force on the wagon.' According to Newton's Third Law, the forces exerted by the horse and the wagon are indeed an action-reaction pair and are equal in magnitude but opposite in direction. However, these forces act on different bodies (the horse and the wagon), and as such do not cancel each other out because they are not acting on the same body.

Therefore, the horse exerts a force on the wagon, but the wagon's opposing force does not cancel out this force on the wagon itself. The unbalanced force applied by the horse on the wagon is what accelerates the wagon. Remember, any acceleration that an object experiences is the result of net external forces. In this case, the net external force producing acceleration is the horse's force on the wagon, not the reaction force of the wagon on the horse.

To elaborate on Newton's Third Law, the two forces (horse on wagon and wagon on horse) are distinct forces that do not directly interact or cancel each other out.