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Blood flows at 0.25 m/s in an artery of radius 0.40 cm.

Try it on paper first. A hint, the key idea and the worked solution are here when you need them.

Blood flows at $0.25\ \text{m/s}$ in an artery of radius $0.40\ \text{cm}$ . Where fat has built up on the wall, the radius is only $0.25\ \text{cm}$ . Find the speed there, and how much lower the pressure is. (Blood $1060\ \text{kg/m}^3$ ; treat it as ideal.)

Need a reminder? The key ideaShow

Bernoulli's equation: along a streamline of an ideal fluid in steady flow, $p + \tfrac12\rho v^2 + \rho gh$ is the same. In a level pipe, $p_1 - p_2 = \tfrac12\rho(v_2^2 - v_1^2)$ : faster means lower pressure.

The worked solution

Have you tried it?

Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.

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