So, v one is 1.59 meters per second similarly,

the two downstream is q over a two is equal to 6.37 meters per second.

So, plugging in all the numbers, we have p two over

gamma is p one over gamma p one is a hundred and twenty kilopascals.

And that should be a hundred and twenty there,

times ten cubed divided by ninety eight hundred the specific weight.

And continuing on here with the elevations, and

separating out all those numbers, the different heads are given there.

So, the answer is p two, the pressure head of p two over gamma,

the pressure head at station two is 4.26 meters,

the closest answer is b, 4.3 meters.

It wasn't asked, but if you want to continue with this and

calculate the actual pressure at station two is equal to

specific weight gamma times 4.26.

So, is equal to ninety eight hundred times 4.26 or 41.7 kilopascals.

Now also, it's instructive to compute all of these head terms in this equation.

So, at station one here, we have the elevation z one is one meter

then the first term here is p one over gamma is the pressure head.

And that is the height to which the liquid column in the static pressure tube rises.

So, that distance is 10.2 meters, this distance,

the distance from the top of the pitot tube, to the pitot static tube,

is the local velocity head, v squared over 2 g or 0.13 meters.

And the height that this rises to, is by definition, the energy grade line.

Similarly, at station two here, this elevation is five meters,

this distance is the pressure head,

p two over gamma which is this term, which is 2.07.

And this distance, the difference between the distance between the two

liquid levels is the velocity head downstream v two squared over two g.

Which is, I'm sorry, that is 2.07 meters and this term,

the pressure head, is 0.13 meters.

If you add all of these terms up, you'll find that this elevation is constant.

In other words, the height that these levels rise to

is the energy grade line which is, by definition, constant or

horizontal because there are no energy losses or gains in the system.

And the energy gain grade line passes through

the fluid level at the top of the pitot tube.

Similarly, this height here,

the distance between these two lines is the velocity head, v squared over two g.

And the height that that level rises to is the hydraulic grade line,

which is dropping in this case.

So, compute all these heights here and

just convince yourselves that indeed the height of the energy grade line

is constant, which it must be from Bernoulli equation.

Now, let's look at some situations where we have head losses

due to friction in the pipe.