Conservation laws, including those for energy, momentum, and angular momentum, are consequences of the action principle. This article introduces the action principle and the resulting conservation laws in the context of newtonian physics, using a model of a system of objects that interact with each other through instantaneous forces. This includes Newton's model of gravity as a special case (article 50710).
Article 46044 introduces to the action principle using the lagrangian formalism, which is more general, and article 12342 uses that formalism to study conservation laws.
