Water flows through the horizontal pipe shown below under la

Water flows through the horizontal pipe shown below under laminar conditions. All the cross section are the same, accept one which is slightly smaller. which one of section; a, B, C, D or t are the smallest, explain why.

Solution

The cross section of C is small in the horizontal pipe. In a horizontal pipe gravitational potential energy of the fluid is constant, so if kinetic energy per unit volume rises (the fluid flow speeds up in a constriction) the pressure energy must fall.