three different liquids are used in a manometer.

Question

(a) derive an expression for P1-P2 in terms of ro(a), ro(b), ro(c), h1, and h2

(b) suppose fluid A is methanol, B is water, and C is a manometer fluid with a specific gravity of 1.37; pressure P2=121.0 kPa; h1=24.0 cm. Calculate P1(kPa).

Answer 1

P1-P2=ro(b)+ro(c)-ro(a)

P1=121.0kPa+[(1.00g/cm3)(980.7cm/s2)(30.0cm)(1dynes/1gcm/s2)]+[(1.37g/cm3)(980.7cm/s2)(24.0cm)(1dynes/1gcm/s2)]-[(.792g/cm3)(980.7cm/s2)(54.0cm)(1dynes/1gcm/s2)]
P1=121.0kPa+(2.94kPa+3.22kPa-4.19kPa)
P1=121.0kPa+1.97kPa
P1=123.0kPa

I think this is right, I just did it for homework.

Answer 2

I got the same answer

Answer 3

Suppose fluid A is methanol, B is water, and C is a manometer fluid with a
specific gravity of 1.37; pressure P2 = 121.0 kPa; h1 = 33.0 cm, and h2 = 25.0
cm. Calculate P1 (kPa).