Question

Question 1

Find the wall tension (in N/m) in the aorta and a capillary under the following assumptions.

(a) The average blood pressure in the aorta is 100. mmHg, and the diameter of the aorta is 1.51 cm.

---------- N/m

(b) The average blood pressure in the capillary is 25.0 mmHg, and the diameter of the capillary is 8.14 µm.

----------- N/m

Questoin 2

Water is transported upward in a plant through xylem tissue, which consists of cells of 1 mm length and a diameter of 335 µm. The xylem cells are attached to each other to form a channel. To what maximum height can water rise in these xylem channels due to capillarity? For those interested: Confirm this result with a simple experiment: Cut and split the stem of a flower with white petals (e.g., a dahlia or a carnation) and place one half the stem in a glass with dilute red ink and the other half in a glass with dilute blue ink. After several hours the flower will be half red and half blue.

---------- m

Answer 1