Two water reservoirs A and B are connected to each other through a 39-m-long, 2-cm-diameter cast iron pipe with a sharp-edged entrance. The pipe also involves a swing check valve and a fully open gate valve. The water level in both reservoirs is the same, but reservoir A is pressurized by compressed air while reservoir B is open to the atmosphere at 95 kPa. If the initial flow rate through the pipe is 1.5 L/s, determine the absolute air pressure on top of reservoir A. Take the water temperature to be 10°C. The density and dynamic viscosity of water at 10°C are rho = 999.7 kg/m3 and μ = 1.307 × 10–3 kg/m·s. The loss coefficient is KL = 0.5 for a sharp-edged entrance, KL = 2 for a swing check valve, KL = 0.2 for the fully open gate valve, and KL = 1 for the exit. The roughness of a cast iron pipe is ε = 0.00026 m.

The absolute air pressure, on top of reservoir is 3858.84 kPa

Explanation:

Given

Since

Also,

, hence

KL = 0.5 + 2  +0.2 = 2.7

Pressure loss of pipe =

f from Moody chart at μ = 1.307 × 10⁻³ kg/m·s and

Roughness ε = 0.00026 m whereby, relative roughness is ε/d = (0.00026 m)/ 0.02 m = 0.013

f= 0.042 and

Q = v·A = 1.5 L/s = 0.0015 m³/s

v = Q/A where A = π·(0.02²)/4 = 3.1416×10⁻⁴ m²

v = (0.0015 m³/s)÷(3.1416×10⁻⁴ m²) =4.775 m/s

Pressure loss of pipe,     = 3733071.965 Pa

 = 3858839.04 Pa

The absolute air pressure, on top of reservoir = 3858.84 kPa

the equation above shows how temperature f, measured in degrees fahrenheit, relates to a temperature c, measured in degrees celsius. based on the equation, which of the following must be true?

a temperature increase of 1 degree fahrenheit is equivalent to a temperature increase of

5

9

degree celsius.

a temperature increase of 1 degree celsius is equivalent to a temperature increase of 1.8 degrees fahrenheit.

a temperature increase of

5

9

degree fahrenheit is equivalent to a temperature increase of 1 degree celsius.

a) i only

b) ii only

c) iii only

d) i and ii only

answer:

the fed will purchase bonds from banks to inject money into the banking system. the banks can use these funds to provide loans to individuals and businesses.

explanation: