Question

Water is pumped from a storage tank into a tube of 3.00 cm diameter (inner) at a rate of

0.001m3/s. What is the specific kinetic energy of the water? (Include all units and conversions)

Answer 1

Specfic kinetic energy = kinetic energy per unit mass

1/2mv² / m = 1/2v²

we have flow rate of 0.001 m³/s

we know that Q = AV

where A = area of cross section ,from where liquid flows

V = velocity of liquid flowing

Area of cross section(circular) = πd²/4 where d = diameter of pipe = 3 cm = 0.03 m {in SI unit as Q is in m³/s}

= 22/7 x (0.03m)² /4

A = 0.000707 m²

putting this value in equation

0.001m3/s = 0.000707 m² x V

V = 1.414 m/s

specific kinetic energy = 1/2V² = 1.0007J/kg

Ans = 1.0007 J/kg