Mass as a Fundamental Dimension

Atoms are made up of even smaller particles we call electrons,protons, and neutrons. In your first chemistry class you will study these ideas in more detail, if you have not yet done so. Some of you may decide to study chemical engineering, in which case you will spend much more time studying chemistry. But for now, remember that atoms are the basic building block of all matter. 

what does all this have to do with mass Mass provides a quantitative measure of how many molecules or atoms ate in a given object. The matter may change its phase, but its mass remains constant. Some of you will take a dass in dynamics where you will learn that on a macroscopic scale mass also serves as a measure of resistance to motion. You already know this from your daily observations. Whidi is harder to push, a motorcyde or a truck As you know, it takes more efibrt to push a truck. When you want to rotate something, the distribution of the mass about the center of rotation also plays a significant role. The further away the mass is located om the center of rotation, the harder it wiU be to rotate the mass about that axis. A measure of how hard it is to rotate something with respect ro center of rotation is called mass moment of inertia. We will discuss this in detail in Section 9-5. 

Mass also pkys an important role in storing thermal energy. The more massive something is, the mote thermal energy you can store within it. Some materials are better than others at 

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