Final answer:
The velocity of blood increases by a factor of 10 as it passes through a blockage.
Step-by-step explanation:
To determine the factor by which the velocity of blood increases as it passes through a blockage, we need to consider the relationship between flow rate, pressure difference, and the radius of the artery.
According to Poiseuille's law, the flow rate through a cylindrical tube is directly proportional to the fourth power of the radius and the pressure difference, while inversely proportional to the viscosity of the blood.
Since the flow rate is reduced to 10.0% of its normal value, the factor by which the velocity of blood increases is the reciprocal of this reduction, which is 1/0.1 = 10.
Hence, the velocity of blood increases by a factor of 10 as it passes through the blockage.