Here's a breakdown:
* Gravity: This is the force that pulls objects towards the center of the Earth.
* Normal Force: This is the force exerted by a surface on an object that is in contact with it. It acts perpendicular to the surface.
How it works:
When an object is placed on a surface, gravity pulls it downwards. The surface, in turn, pushes back on the object with an equal and opposite force, which is the normal force. This upward force counteracts the downward force of gravity, preventing the object from falling through the surface.
Examples:
* A book resting on a table experiences a normal force from the table that balances the force of gravity acting on the book.
* A person standing on the floor experiences a normal force from the floor that balances their weight (which is due to gravity).
Key Points:
* Normal force is always perpendicular to the surface.
* Normal force is a reaction force to the force exerted by the object on the surface.
* The magnitude of the normal force is equal to the weight of the object when the object is at rest on a horizontal surface.
