Please see : Spring (mathematics) - Wikipedia, the free encyclopedia

This is the forumula they give.

where

*R*is the distance from the center of the tube to the center of the helix,

*r*is the radius of the tube,

*P*is the speed of the movement along the z axis.

Ok, the helix will be 400 wide, so R = 200 units.

The radius of the tube will be 30, so r = 30 units.

Now this is where im stuck, they ask for P for the speed it moves upwards / downwards. How should i get this? For example if i want my spring to have 2 complete revolutions and have a total height of 500 units, how should i know what P is?

I also need to know n, which is not explained very well what n is on the page.

Many thanks if you can help me understand.