However, the key point is that normal force only exists when there is contact between the object and a surface.
Here's why objects fall:
* Free Fall: If an object is not in contact with a surface, there is no normal force to counteract gravity. This is why objects fall when dropped.
* Air Resistance: Even with air resistance, objects still fall. Air resistance opposes the downward motion, but doesn't completely negate the force of gravity. The object accelerates downwards until it reaches terminal velocity, where air resistance balances gravity.
* Net Force: The net force acting on an object determines its motion. When the net force is zero, the object is at rest or moving at a constant velocity. When the net force is not zero, the object accelerates. In the case of falling objects, the net force is downwards due to gravity, causing the object to accelerate downwards.
In summary:
* Normal force is a contact force. It only exists when there is a surface pushing back on an object.
* Gravity is a non-contact force. It acts on all objects with mass, regardless of contact.
* Objects fall because the force of gravity is not counteracted by any other force. In the case of free fall, there is no normal force, and in the case of falling through air, air resistance only partially counters gravity.
