First slide

Fluid dynamics

Question

Water is flowing through a horizontal pipe of varying cross-section. If the pressure of water equals 2 cm of mercury, where the velocity of the flow is 35 cms^-1, what is the pressure at another point, where the velocity of flow is 65 cms^-1?

Easy

A

1.02 cm of Hg
B

1.88 cm of Hg
C

2.42 cm of Hg
D

1.45 cm of Hg

Solution

From Bernoulli's theorem
$P_{1} + \frac{1}{2} {ρv}_{1}^{2} = P_{2} + \frac{1}{2} {ρv}_{2}^{2} P_{2} = ρ_{1} + \frac{1}{2} ρ (v_{1}^{2} - v_{2}^{2}) = 2 \times ρ_{Hg} g + \frac{1}{2} \times 1 [{(35)}^{2} - {(65)}^{2}] {hρ}_{Hg} g = 2 \times ρ_{Hg} g - 1500 \Rightarrow h = 2 - \frac{1500}{13.6 \times 980} = 1.88 cm$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App