Drawing a simple vector field issue

1. Mar 22, 2007

mr_coffee

Hello everyone i'm not sure if this is right or not...

If i have

F(x,y,z) = zj; where j is the vector, j hat.

Would that be all vectors are going to be pointing up if you assume z is up, and are in the y plane?

If the coordinate sytem is, z is up, y is to the right, and x is pointing at you.

If i had F(x,y,z) = yj; the answer is, No vectors emanate from the xz plane since y = 0 there. In each plane y = b, all the vectors are identical.

2. Mar 22, 2007

Dick

No. j is a unit vector pointing in the same direction as the +y axis. Which you seem to want to call 'right'. The length of the vectors is proportional to their z coordinate. What is the 'y plane'? What does 'in' a plane mean? Parallel to?

3. Mar 22, 2007

mr_coffee

I worked it out and it seems the vectors are pointing parrallel to the +y axis which is pointing right, for values > 0, and for values < 0 its pointing to the left or in the -y direction.

4. Mar 22, 2007

Dick

That's the right picture (where 'values' means z, right).

5. Mar 22, 2007

HallsofIvy

Staff Emeritus
z is a number, j is a vector pointing in the positive y direction. Your vector field consists of vector pointing in the positive y direction, longer as z increases. (And pointing in the negative y direction for z negative.)