Final answer:
The blood vessel's radius is reduced to 60.0% of its initial diameter by plaque buildup. To maintain a constant flow rate, the body must increase the pressure difference along the vessel by a factor of approximately 1.67. Turbulence created by the obstruction further affects the flow rate.
Step-by-step explanation:
In this scenario, the blood vessel's radius is reduced to 60.0% of its initial diameter due to plaque buildup. To compensate for the reduced diameter and maintain a constant flow rate, the body must increase the pressure difference along the vessel.
To calculate the factor by which the pressure difference must increase, we can use the formula:
Factor = 1 / (1 - Diameter reduction)
Using this formula, the pressure difference must increase by a factor of 1.67 (approximately) to maintain a constant flow rate.
If turbulence is created by the obstruction, it would further affect the flow rate. Turbulence increases the resistance to flow, leading to a decrease in the flow rate.