Hi, could really do with some help on these!?

the first one is relatively simple. Water travels through an enclosure(pipe) that is normally 1/2 to 3/4 " in diameter and the system in which it travels is pressurized by the volume of water it contains. So when that system is turned on and allows the water to freely flow the systems pressure forces it out through the "tap"and at the point in which it exits the tap the pressure is greatest and at the lowest point of its fall from the opening pressure is less, gravity takes cares of the rest.