Newton's three Laws of Motion
Gravity, Conservation of Mass, and Momentum
Law of Gravity
The law of Gravity states that any two bodies in the universe attract each other with a force that is proportional to they're mass and is inversely proportional to the distance between them.
The Law of Conservation of Mass
This law states that for any system closed to all transfers of matter and energy, the mass of the system must remain constant over time, as system mass cannot change quantity if it is not added or removed.
Law of Conservation of Momentum
The law of conservation of mass states that for any system closed to all transfers of matter and energy, the mass of the system must remain constant over time, as system mass cannot change quantity if it is not added or removed. Hence, the quantity of mass is "conserved" over time.