Question

If action is equal to reaction then how horse can pull a cart ?

Why don't the forces cancel each other ?

Pls explain

Answer 1

Newton's third law of motion state that when an object exerts a force on another object, the second object instantaneously exert a force back on the first. These two force are always equal in magnitude but oppsite in direction. These forces acts on different objects and never on the same object. When a horse pushes the ground, the ground reacts and exerts a force on the horse in the forward direction. The force is able to overcome friction force of the cart and it moves.
Action and reaction both are not acted on the same body. So there is no chance of cancellation.