Hello, I need some help learning how to calculate the volume of a Spring. The only resource i can find is on wikipedia, but i am having trouble understanding it.

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

This is the forumula they give.

where

Ris the distance from the center of the tube to the center of the helix,

ris the radius of the tube,

Pis 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.