1. Gravity: This is the force of attraction between any two objects with mass. On Earth, gravity pulls objects towards the center of the planet, causing them to fall downwards. Gravity is what keeps us on the ground and what makes objects accelerate when dropped.
2. Friction: This force opposes motion when two surfaces rub against each other. Friction can be caused by the roughness of the surfaces, and it converts some of the object's energy into heat. There are different types of friction, including static (when an object is at rest), kinetic (when an object is moving), and rolling friction.
3. Applied Force: This is any force that is directly applied to an object by an external source. It can be a push, a pull, or a force caused by an interaction like a magnet or a spring. Applied forces can cause an object to start moving, stop moving, or change its direction of motion.
Let me know if you want to know more about these forces or how they work together!
