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Hey, welcome to another episode of Measuring Matters. I bet you’re probably wondering
why I’m sitting here with all this water and these empty tumblers. Well, you see, I
was asked to transfer exactly 4 ounces of water from this cup into one of these tumblers.
Maybe you’ve had to complete a task like this at some point. Maybe you didn’t know
how to measure exactly 4 ounces. In this short video, you’ll learn how to measure liquids
using a new tool called a graduated tumbler. You might be asking yourself what this is.
No, it’s not a tumbler that doesn’t have to go to school anymore. It’s simply a tumbler
with markings on the side. The markings are set at measured increments or levels. That’s
what it means to be graduated. We need to know a few things about how liquids
act before we start to measure them. When a liquid is poured into any container, it
will fill the container and form a level surface at its highest point. When you look close
though, that highest level isn’t quite level. You’ll notice that it’s a bit higher at
the edges and a bit lower in the center. That’s a unique feature of liquids. It’s called
a meniscus, and it’s the key to making an accurate measure. You want to make your reading
at the bottom of the meniscus, or lowest point. This is the true level of liquid in your tumbler.
You need to be careful though, liquids can also play tricks on your eyes. Some liquids
can actually cause light to refract, or bend. In order to avoid this and make an accurate
measurement, you’ll need to make sure the meniscus is at eye level.
The easiest way to do this is to place the tumbler on a flat, level surface and position
yourself so that your eyes are at the same level as the liquid in the tumbler. When you
do this, simply read the measurement you see. As you can see, this is exactly at 4 ounces.
OK, let’s recap what we’ve learned. This new tool is called a graduated tumbler. Liquids
have a unique property which causes a meniscus to form when they are placed in a tubular
container. You should read your measurement at the bottom of the meniscus. Last, remember
that eye level is key. That’s it, you should be all set! You’re
ready to start measuring liquids with your new tool. Before you know it, the tumbler
won’t be the only thing that’s graduated!