Friction is basically the force that opposes motion between two surfaces that are in contact.
Anytime two things try to slide past each other, friction shows up like:
“Not on my watch.” 😭💀
The friction that keeps an object from starting to move.
Example: Pushing a heavy box and it refuses to even shift — that’s static friction acting strong.
The friction that acts when an object is already moving.
It’s usually less than static friction (once you start moving, it feels easier).
Friction when an object rolls over a surface (like a car tire).
It’s smaller than sliding friction — that’s why wheels are a cheat code.
Friction that happens in air or water.
Example: Air resistance on a fast-moving car, or swimming through water.
It may be annoying, but we literally can’t live without it:
Helps us walk without slipping
Allows cars to move and stop
Helps you hold things
Enables writing (pen on paper friction)
Causes wear and tear on machines
Wastes energy as heat
Slows things down even when you don’t want it 🥲
Lubrication (oil, grease)
Smooth surfaces
Using wheels/ball bearings
Streamlined shapes to reduce air resistance