Answer:
![0.12 mm^(2)](https://img.qammunity.org/2020/formulas/physics/college/darvkf8epjzu2t3uq8p8rkfnnmqz8895a7.png)
Step-by-step explanation:
= flow speed in the region of the partial blockage = 5100 mm/h
= flow speed in the clear region of nearby vessel = 1200 mm/h
= Cross-sectional area for the clear region = 0.51 mm²
= Cross-sectional area for the region near the blockage
According to equation of continuity, Volume flow rate must remain same at all points. hence
![A_(1) v_(1) = A_(2) v_(2) \\A_(1) (5100) = (0.51) (1200)\\ A_(1) (5100) = 612\\\\ A_(1) = (612)/(5100) \\\\ A_(1) = 0.12 mm^(2)](https://img.qammunity.org/2020/formulas/physics/college/hlz0opw1nfs5q7342orl1oz5p1ticcgrmi.png)