NGSS
Friction explained in an easy to understand way.
Inertia explained in an easy to understand way.
Momentum
The product of an object's mass and velocity. Momentum. Momentum is how much motion an object has, and it depends on how heavy it is and how fast it's moving.
Motion explained in an easy to understand way.
Static friction
Friction that acts on objects that are not moving. Static friction. Static friction is what keeps objects from sliding when they are still.