# ^Position of an arbitrary point P at any time is described using cartesian coordinates i.e. P (x,y, z).

**Position **

^Position of an arbitrary point P at any time is described using cartesian coordinates i.e. P (x,y, z).

For 1 D motion along x axis, y & z coordinates are zero, where as x coordinate may be + ve or – ve.

**1, 2 & 3 – D motion**

If coordinate required to specify the position of a moving object at any instant are;

- then motion is called 1 D e.g. moving along a straight line without turning.
- then motion is called 2 D e.g. an object moving along a circle.
- then motion is called 3 D e.g. random motion of gas particles