Step-by-step explanation:
If two persons are applying forces on two opposite sides of a moving cart and the cart still moves with the same speed in the same direction we can infer that the magnitudes of the forces applied by the two persons are equal and the direction of the forces is opposite to each other.
This is because of Newton's First Law of Motion which states that an object will remain at rest or in uniform motion in a straight line unless acted upon by an external force. In this case the cart is already in motion and is moving in a straight line. The forces applied by the two persons are external forces acting on the cart. Since the cart is moving with the same speed and in the same direction we can infer that the forces applied by the two persons are equal in magnitude and opposite in direction.
This is also known as the principle of action and reaction which is the third law of motion. According to this law for every action there is an equal and opposite reaction. In this case the action is the force applied by the two persons on the cart and the reaction is the force exerted by the cart on the two persons in the opposite direction.