The Head Form of Bernoullis Equation

In many problems, particularly those involving flow of water in dams, canals, and open channels, it is convenient to divide both sides of Eq. 5.7 by g to find 

Every term in Eq. 5.11 has the dimension of a length. The lengths are at least conceptually convertible to elevation Az above some datum plane. These elevations are commonly referred to as heads Thus, we refer to the various 

There is no simple, universal rule for deciding when to use the head form of Bernoulli s equation and when to use the energy form, Eq. 5.7 if correctly applied, both give the same result. Through practice engineers learn which is more convenient for a given problem. 

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