If you’ve taken our MOST water math courses online, or purchased our MOST Water Math DVD (still only $50, for over ten hours of step-by-step math problem solutions), or attended any of our classes at College of the Canyons or the California-Nevada Section of the American Water Works Association, this week’s blog posts won’t be anything new to you. In fact, they won’t be new if you’re a long time reader of this blog. With the California Water Distribution Operator certification exam this coming Saturday, we will be reviewing the MOST important five math formulas. In fact, we call them the MOST Five.
If you don’t want to wait all week, you can get much of what we will be posting this week right now. From the MOST home page, go to the bottom of the screen and enter “Water Math” in the Search box. Look especially in April and May of 2010 (yes, we’ve been posting for over four years now!) You can also go to our YouTube site for a few short math videos.
Today, we revisit the “KISS Principle”: Keep it simple, stupid! And the simplicity comes from recognizing that, while the State gives you a full page of — mostly useless! — formulas, you really only need to know five to solve almost every single problem you’ll encounter. That’s right! Only five! The MOST Five, shown here.
Each day this week we’ll highlight one of the five, just to get you primed for Saturday’s exam. Today’s formula is Volume = Area x Height, shown in the lower left corner of our MOST Five.
Use this formula to find the Volume of any regularly shaped space, such as a pipeline or a storage tank. Notice that it doesn’t matter if the “base” — the cross-sectional Area of the volume — is a circle or a rectangle. That is addressed by how you calculate the Area. If you know the dimensions — length, width, and height, or diameter and height — of your Volume, this is your formula. But be careful: Volume can be calculated from four out of the MOST Five formulas! Which one will you use?
Look for the “keys”. In the MOST Five seen here, each formula has a variable shown in a red font. That indicates a variable that only shows up in one location. And if you have that variable or you are looking to find it, then you know which formula to use: the only one with that variable! The key for this formula is the Height.
If we have — or can find from other information in the problem — the Volume and the cross-sectional Area, then we can find the Height. This usually shows up as a question asking for the depth of water in a storage tank.
The final variable in this formula is the Area — once again, that is the cross-sectional area of our Volume. This is the least likely test problem to be explored with this formula. This will show up if you are asked to determine the diameter of a pipe, knowing the length (or Height, in our formula) and the Volume of water in the pipe. You first find the Area, then find the Diameter using Area = 0.785 d2, working backwards — with the square root key — to get to Diameter.
Stay tuned this week as MOST gives you a Water Math tune-up for Saturday’s exam.