You get them at the start of the game, but there is just one more per area.
In general, a pressure is a force per unit area, across a surface.
This value is usually expressed as energy per unit wall area.
Pressure is the amount of force acting per unit area.
It has the same power per unit area at the center of the receiving spot on the ground.
Note that stress has units of pressure, or force per unit area.
The deeper you go in a fluid, the greater the pressure (force per area).
In general, crop rotation levels per unit area are very low.
Note that the represents the line charge per unit area in the plane.
A very rough surface has many more molecules per unit area to be hit by light.