Drawing a radial vector field

 Objective: draw a radial field

Considerations

A radial field models certain types of gravitational fields and energy source fields. To draw a vector field you have to draw a vector at each point of a set of points. Let's say that you have to draw the vector F(2.1) = <1.1/2>, you draw first the point (2,1) then you move one unit to the right and half unit up. The tail of the vector is at the point (2,1).

In a radial field all the vectors point directly toward or away from the origin. The vector located at (x,y) is perpendicular to the circle centered at the origin and passing through (x,y). All the vectors on that circle have the same magnitude.

Method to draw a radial field

1) Choose a sample of points from each quadrant in the system of coordinates plane. It's better to choose a set of points at the intersection of the grid lines.

2) Draw the corresponding vector at each point

Example

Solution

Figure (a) shows the vector field. Figure (b) shows circles overlain on the vector field.

Practice