Answer:
Explanation:
First, we are going to need the water specific volume at 15ºC: v=0.001001 . The density '' of the water is the inverse of the specific volume:
First, consider the mass flow, which is related to the volumetric flow (density and velocity) and the area:
The area of each cross-section is:
(in square meters). Here, the radius was not used but the diameter, which means a division by 4 (2 squared).
From mass flow isolate the velocity and calculate it:
The work of the pump is calculated considering an energy balance on the pump:
Considering the isentropic process may give us the relation:
Applying that to the pump,
Multiplying it by the mass flow:
The work is negative because it is entering to the system, but the required is positive. (It is just a standard rule)