Newtons 1st Law
Newton's First Law of Motion states that an object in motion will stay in motion unless an external force acts upon it or if the object is at rest, it will remain at rest unless an unbalanced force acts on it.
Net Force
Net force is the total of all forces acting on an object.
Inertia
A property of matter in which it stays at rest or travels at a constant velocity along a straight line as long as another external force doesn't upon it.
Gravity
a force applied by all object that affects surrounding objects, pulling them towards each other.
Normal Force
the force that is applied by an object when a different object applies force on it.
Friction
A force applied across a surface that opposes the direction of motion.