Definition of Water Pressure

• The pressure of any liquid is defined as force per a unit of area perpendicular to a plane. This can be measured in units such as pounds per square inch (psi). Water pressure is how much force the water exerts on a surface per area when the water hits that surface perpendicularly.
  
  

The Physical Production of Water Pressure

• Water pressure can be increased by decreasing the area through which the water travels or by increasing the speed of the water. This increases pressure because of the physical property that it is extremely difficult to compress or increase the density of water. Pressure is, hence, always increased when area is reduced or the speed at which the water flows is increased.
  
  

How Water Pressure Is Increased

• Water pressure is generally increased by forcing water at a constant speed down a series of smaller and smaller pipes. As water traveling through and filling a larger pipe is forced into a smaller pipe, it has to move faster in order to make room for the water behind it. This means that the water's speed will be enhanced and area will be decreased, thus increasing pressure.