Motion in a plane: Polar coordinates
Motion in a plane: Polar coordinates;
The above figure shows the polar coordinates r and q that represent the position of a particle moving on a curved trajectory. An arbitrary fixed line such as the x-axis is used as a reference for the movement of q . Unit vectors and are established in the positive r and q direction respectively. The position vector r to the particle at A has a magnitude equal to the radial distance r and a direction specified by the unit vector .
In this figure, magnitude of is dq.
In the same way, it can be shown that