Constraint (classical mechanics)

In classical mechanics, a constraint on a system is a parameter that the system must obey. For example, a box sliding down a slope must remain on the slope. There are two different types of constraints: holonomic and non-holonomic. First class constraints and second class constraints Primary constraints, secondary constraints, tertiary constraints, quaternary constraints. Holonomic constraints, also called integrable constraints, (depending on time and the coordinates but not on the momenta) and Nonholonomic system Pfaffian constraints Scleronomic constraints (not depending on time) and rheonomic constraints (depending on time). Ideal constraints: those for which the work done by the constraint forces under a virtual displacement vanishes.