Text density

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DENSITY

Density is a word we use to describe how much space an object or substance takes up (its volume) in relation to the amount of matter in that object or substance (its mass). Another way to put it is that density is the amount of mass per unit of volume. If an object is heavy and compact, it has a high density. If an object is light and takes up a lot of space, it has a low density.So, if we know the volume and mass of an object, we can calculate the density using the equation density = mass / volume.

Finding Mass and Volume. Mass

How do we go about finding those two properties of matter? Let's start with mass, which we've learned is a measurement of the amount of matter in an object or substance. Mass is very important because it's a universal measurement - it's used by scientists all over the world and even astronauts on the International Space Station. That's because, unlike weight, mass doesn't change due to changes in gravity. A huge block of ice, for example, weighs much less in space because of lower gravity, but its mass is always the same.
Volume - how much space an object or substance takes up - is measured in cubic meters, but you'll more commonly see it in the simplified form of liters (expressed as L) and milliliters (mL). We often use measuring cups (like the ones in your kitchen!) to find out how much volume a substance has, though we can also find the volume of an object by measuring its sides.
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Bridge Background
Inventions are created to solve problems, and bridges solved the very big problem of trying to cross lakes, rivers, and deep valleys. Some of the earliest bridges were made by using large fallen logs from trees. They have definitely come a long way since then, thanks to technology and engineering. Let's discover some of the most famous and impressive types of bridges
Arch Bridges need to be able to support the weight, also called the load, of the objects (people, cars, trucks, etc.) on it. Therefore, the structure underneath the bridge needs to be able to get the job done. The underside of bridges looks different when you are comparing different types, and the arch bridge has perhaps one of the most architecturally distinctive undersides. You see, arch bridges have a curved underside. It looks like someone cut a semicircle out of the bottom of the bridge.
Arch bridges are some of the most beautiful bridges in the world. Come and learn about what arch bridges are, their history, real world examples and pros and cons of this bridge type.Bridges provide a very important function in allowing easy transport over a body of water, and they look good doing it! While there are several types of bridges, one of the oldest is the arch bridge. Bridges need to be able to support the weight, also called the load, of the objects (people, cars, trucks, etc.) on it. Therefore, the structure underneath the bridge needs to be able to get the job done.