a mass sits at rest on top of a table. which two forces are action-reaction pair forces and thus are equal and opposite?
weight (force of gravity), and the table pushing upward to hold the mass.
According to Newton's third law of motion, for every action, there is an equal and opposite reaction. In this case, let's consider the forces acting on the mass sitting at rest on top of the table.
The force exerted by the mass due to gravity is acting downwards. This force is called the weight of the mass. According to Newton's third law, the table exerts an equal and opposite force upwards on the mass. This force is called the normal force.
Therefore, the two forces that form an action-reaction pair and are equal and opposite are the weight of the mass downwards and the normal force exerted by the table upwards.
The two forces that form an action-reaction pair, also known as Newton's Third Law of Motion, are the normal force and the gravitational force. When a mass is at rest on top of a table, there are two forces acting on it: the force of gravity pulling it downward and the normal force exerted by the table pushing it upward. According to Newton's Third Law, these two forces are equal in magnitude and opposite in direction.
To determine the answer to this question, you need to understand the concept of action-reaction pairs and analyze the forces acting on the mass. Here's the step-by-step process:
1. Identify the forces acting on the mass: In this case, there are two forces - the force of gravity and the normal force.
2. Understand Newton's Third Law: Newton's Third Law states that for every action, there is an equal and opposite reaction. This means that the forces in an action-reaction pair are equal in magnitude but act in opposite directions.
3. Compare the forces: The force of gravity pulls the mass downward, acting vertically downward. The normal force, exerted by the table, pushes the mass upward, acting vertically upward.
Since the normal force and the gravitational force are acting in opposite directions and have the same magnitude, they form an action-reaction pair. Thus, the normal force and the gravitational force are the two forces that are action-reaction pairs and are equal and opposite.