Here's why:
* Gravity pulls objects down.
* The normal force pushes objects up.
This is why you don't fall through the floor! The floor exerts an upward force (normal force) equal to your weight (the force of gravity pulling you down).
Other forces that can oppose gravity:
* Buoyancy: The upward force exerted by a fluid (like water or air) on an object submerged in it.
* Thrust: The force that propels an object forward, like the force from a rocket engine.
* Lift: The force that acts perpendicular to the direction of motion of an object, like the force on an airplane wing.
It's important to remember that these forces can act in opposition to gravity in specific situations. For example, buoyancy will oppose gravity only when an object is submerged in a fluid.
