en.wikipedia.org/wiki/Momentum

... the total momentum is constant. This fact, known as the law of **conservation of**
**momentum**, is implied by Newton's laws of motion.

www.physicsclassroom.com/class/momentum/u4l2b.cfm

This law of **momentum conservation** will be the focus of the remainder of Lesson
2. To understand the basis of **momentum conservation**, let's begin with a short ...

www.khanacademy.org/science/physics/linear-momentum/momentum-tutorial/a/what-is-conservation-of-momentum

Learn what **conservation of momentum** means and how to use it.

www.grc.nasa.gov/www/k-12/airplane/conmo.html

The **conservation of momentum** is a fundamental concept of physics along with
the conservation of energy and the conservation of mass. Momentum is defined ...

scienceworld.wolfram.com/physics/ConservationofMomentum.html

This entry contributed by Leonardo Motta. **Conservation of momentum** is a
fundamental law of physics which states that the momentum of a system is
constant if ...

www.britannica.com/science/conservation-of-momentum

**conservation of momentum**: General law of physics according to which the
quantity called momentum that characterizes motion never changes in an
isolated ...

hyperphysics.phy-astr.gsu.edu/hbase/conser.html

In mechanics, examples of conserved quantities are energy, **momentum**, and
angular **momentum**. The **conservation** laws are exact for an isolated system.

physics.info/momentum-conservation

Start with Newton's third law of motion, toss in the impulse-momentum theorem,
and see ... 1668: John Wallis suggests the law of **conservation of momentum** ...