# Motion in a plane

Two dimensional motions is example for motion in plane. The two dimensions of object use the vector method for motion description. It is very important method for motion. In this, acceleration is one parameter. Constant acceleration means that the velocity vector changes by equal amounts in equal intervals of object equation of motion are equation that describe the behaviour of a physical system in terms of its motion as a function of time, the equations of motion describe the behaviour of a physical system as a set of mathematical functions in terms of dynamic variables: normally spatial coordinates and time are used, but others are also possible, such as momentum components and time. The most general choice are generalized coordinates which can be any convenient variables characteristic of the physical system .The functions are defined in a Euclidean space in classical mechanics, but are replaced by curved space in relativeity. If the dynamics of a system is known, the equations are the solutions to the different describing the motion of the dynamics.

Generally an equation of motion M is a function of the position r of the object ,its velocity and its acceleration and time t .Euclidean vectors in 3rd are denote by in bold function of the position r of the object, its velocity and time t. Euclidean vectors in 3d are denoted throughout in bold. This is equivalent to saying an equation of motion in r is a second order ordinary differential equation in r.
M[r(t),r(t),r(t), t]