Question

39. Water is flowing through a horizontal pipe of varying cross-section. If the pressure of water equals 2cm of
mercury, where the velocity of the flow is 35cms-, what is the pressure at another point where the velocity of
flow is 65 cms-(g=980cms?)
(a) 1.02 cm of Hg (b) 1.88cm of Hg (c) 2.42cm of Hg (d) 1.45cm of Hg​

Answer 1

Answer:

So here your answer for this asked question

first of all let me know you that I have changed the unit from m/s to cm/s for my convenience

Bernouli’s eqn. would be still valid here.

Therefore,

Patm + pgh + 0.5pv^2 = Constant.

Now,

1g1 + 0.5*p35^2 = 1gh + 0.5p*65^2

gh = 1*10*1 + 0.5*1*35^2 – 0.5*1*65^2

gh = 1490 cm

h = 149 cm Hg.

So the pressure at that point will be 149 cm Hg

and convert it into metre its answer will be

1.49 m Hg