Volume Flow Rate, Help??? 1. The problem statement, all variable and given/known data The volume flow rate in an artery supplying the brain is 3.5E-6 m^3/s. (a.) If the radius of the artery is 5.4E-3 m, determine the average blood speed. (b.) Find the average blood speed at a constriction in the artery if the constriction reduces the radius by a factor of 7. Assume that the volume flow rate is the same as in part (a.) 2. Relevant equations Q = Volume flow rate = AV 3. The attempt at a solution I got (a.) but I need help with (b.). I think my radius for part (b.) is wrong, but I don't know how else to get it. For part (a.) I got 0.0382 m/s by using Q = Volume flow rate = AV = pi x r^2 x v = 3.5E-6 m^3/s and using the given radius in part (a.) I solved for v. For part (b.) I divided the given radius by 7, and subtracted that from the original radius to get a radius of 4.63E-3, and I put it into the equation the same way as part (a.) and I got 0.0520 m/s, but it's wrong. Help?