Final answer:
Poiseuille's law is used to calculate the resistance of the hose for concrete flow. The resistance R equals (8ηL)/(πd^4), and with given parameters, one can solve for fluid viscosity and power supplied by the pump for a laminar flow of concrete.
Step-by-step explanation:
The resistance of the hose through which concrete is pumped can be determined by using the applicable form of Poiseuille's law for resistance to laminar flow of an incompressible fluid in a tube. The correct expression for the resistance R is R = (8ηL)/(πd^4). Here, η represents the fluid viscosity, L is the length of the tube, and d is the diameter of the tube. Given the pressure at the pump (ΔP), the diameter of the hose (d), the length of the hose (L), and the viscosity of the concrete (η), we can calculate the resistance of the hose.
To calculate the viscosity of the concrete assuming laminar flow, we rearrange Poiseuille's law to solve for η. For the power supplied by the pump, we can use the formula Power = ΔP × Flow rate, where ΔP is the pressure difference and flow rate is the volume of concrete pumped per unit time. Since it is assumed that the pump and the point of use are at the same level, we can neglect the power supplied to increase the concrete's velocity.