Next, I have a number of questions related to this situation.

The spillway for a dam is 20 meters wide and

is designed to carry 125 cubic meters per second.

A 1:15 scale model is to be constructed.

Firstly, the width of the model should be most nearly which of these alternatives?

So the solution is the length scale ratio is

LP over LM which is also equal to the width,

WP over WM and we're given that this is 15.

It's a one to 15 scale model.

Therefore, the width of the model is the width of the prototype divided by 15.

Which is equal to 1.33 meters, or answer C.

The next question,

the flow rate in the model should be most nearly which of these?

So, again, we have a general relationship, Qr = Lr^2 Vr,

which is always true, But in this case specifically for a Froude number

model from the previous slide we have Qr is Lr to the five halves power.

So therefore, Q model is Qp over lr to the five-halves is equal to that,

and the answer is 0.143 cubic meters per second.

So the closest answer is B, and

that is the flow rate we have to run the model act to get similitude.