QUESTION $1$

A gate valve located at the end of a pipe that is $1500m$ long is suddenly opened. The pipe is connected to a reservoir, and the exit of the pipe is located at a height of $20m$ below the water level. The diameter of the pipe is $d=0\mathrm{.}9m,$ and the friction factor through the pipe can be assumed to be $f=0\mathrm{.}025.$ Calculate the time after the sudden opening of the valve for the velocity to reach $90\%$ of its final velocity. Figure $1$ shows the reservoir.

Figure $1$: Reservoir

$[20]$

QUESTION $2$

Water at the temperature of $20C$ is flowing inside a commercial steel pipe with an internal diameter of $170mm$ and roughness fraction of $0\mathrm{.}046mm.$ The pipe has a length of $150m$ and the pressure difference to overcome friction loss is $55$kPa, calculate the discharge flow rate. Perform two trials only.

$[20]$

QUESTION $3$

In Figure $2,$ a water tank opened to the atmosphere is connected to a pipe $($A$)$ containing oil. Calculate the pressure at point $A$ if the atmospheric pressure is $101\mathrm{.}3$ kPa. All required information is presented in Figure $2.$

$3$