If the velocity at point A is 18 m/s, what is the pressure at point B if we neglect friction? T 15m ☐ 10.5 m D- 75 mm D= 200 mm

QUESTION 4 Adding 20ml sample to a 300ml DO bottle causes its dissolved oxygen concentration to decrease by 10 mg/l. by the end of the first day What is the BOD1 of the sample? Answer mg/L

The diagram below shows a pumping system to pump water to an elevated tank. The next page shows the performance curve of a specific type of centrifugal pump. The loss factors at the inlet and outlet are 0.5 and 1.5 respectively while the loss factor associated with the bend is 1.5. The diameter of the pipe is 0.050 m while the total pipe length is 400 m. In order to simplify the calculation you can assume that the friction factor is f= 0.036. Determine the duty point of this pumping system and thus determine the flow rate of the pump for an impeller diameter of 140 mm? Also determine the shaft power of the pump and give an estimate of the pumps efficiency at the duty point. Given that the pump is located 1.80 m above the water surface (1), and the pipe length from inlet to pump is 6.0 m, determine the NPSHA at the pump and state whether cavitation is likely to occur. Sol: 3.6 m 40 H m 30- P 10 20- K₁ = 0.5 5- kW 2- 1- 13 4 2- NPSH K₁ = 1.5 170 160 150 140. 130_ (1) Q 10 Pump 20 54…

18. The results for sieve analysis is shown in the following table: Sieve No. 10 20 40 60 100 % Passing 69.3 59.1 48.3 38.5 28.4 19.8 4.5 Liquid Limit Plastic Limit Non-Plastic (NP) Non-Plastic (NP)