The following examples illustrate the use of conservation laws in dynamical problems in which there are no dissipative forces. In this tutorial the relevant laws are conservation of mechanical energy and conservation of linear momentum. Conservation laws apply to isolated systems and are useful when motion is transferred from one part of the system to another. In question 3.3 the system is not strictly isolated but we can treat it as such to a sufficient approximation. The moral is simple: dynamics problems are difficult; always begin by asking if anything is (or can be considered to be) conserved.