Why don't you move when you pull a door open and the force the door exerts on you is equal to the force you exert on the door?
When you pull a door open and the force the door exerts on you is equal to the force you exert on the door, you don't move because of Newton's third law of motion, also known as the law of action and reaction. This law states that for every action, there is an equal and opposite reaction.
In this case, when you pull on the door, you apply a force on it in one direction, and according to Newton's third law, the door also exerts an equal force on you in the opposite direction. These forces cancel each other out, resulting in no net force acting on you, and hence, you don't move.
The reason why the door moves while you don't is that there is less friction between the door and the floor compared to the friction between your shoes and the floor. The frictional force between the door and the floor is smaller, allowing the door to overcome this resistance and move, while the frictional force between your shoes and the floor is greater, preventing you from moving.
When you pull a door open and the force you exert on the door is equal to the force the door exerts on you, you do not move due to the concept of balanced forces. To understand why, we need to look at Newton's third law of motion, which states that for every action, there is an equal and opposite reaction.
In this scenario, when you apply force to the door by pulling, the door exerts an equal and opposite force on you. The reason you do not move is that these forces cancel each other out, resulting in a state of equilibrium. It is similar to pushing against a wall with the same amount of force as it pushes back on you – there is no net force acting on you, so you remain stationary.
To further investigate this concept, you can consider the forces acting on both you and the door. Typically, you would have two forces acting on you: the force you exert on the door and the force of gravity pulling you downward. Similarly, the door experiences the force you apply and the reaction force due to friction with the floor. If these forces are balanced and there is no net force, both you and the door will remain still.
In summary, you do not move when pulling a door open with an equal force to the force the door exerts on you because the balanced forces cancel each other out, resulting in a state of equilibrium.