Question 4

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回答: 这考医学院的物理题，我看了头都炸了由 wzg69 于 2020-12-21 01:13:07

这公式也要背啊？ Poiseuille’s Law Flow = ΔPπr⁴ / 8Lη。学物理一般不需要背这个啊

Question 4

The flow rate of stomach content emptying is 100 cm³/sec. Patients who undergo gastric bypass surgery will increase this rate to almost 1600 cm³/sec. Assuming the flow of stomach contents approximates Poiseuille’s Law, what change to their gastrointestinal connection would explain this, provided no other changes occur in the conditions of stomach content flow?

The new connection is 2 times longer.

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The new connection is 4 times longer.

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The new connection radius is 2 times larger.

If we model this GI connection as a pipe, we can quantify the flow using Poiseuille’s Law, which states:

Flow = ΔPπr⁴ / 8Lη

ΔP is the pressure difference across the pipe, r is the radius of the pipe, L is the length of the pipe, and η is the viscosity of the fluid in the pipe. The question states that the flow increased from 100 to 1600 cm³/sec, a 16-fold change. Of all the answers provided, only doubling the radius would result in a 2⁴ increase in the flow.

The new connection radius is 4 times larger.