Lesson 1 - Introduction to Classical Mechanics - What's the Matter?

Everyone at some point in time has heard stories about when people thought the world was flat, the Earth revolved around the Sun, or how the Earth's orbit made music. While those stories may seem silly today, they were ironclad truths in their time. One thing they all had in common however, was that since ancient times, people have been trying to explain the world around them. Ironically enough with each new period of enlightenment, like the television show Lost, more questions followed.

The world known to the earliest physicists was much smaller and less complex than the world today (One may joke that its all relative. If you don't get this joke yet do not worry, you will eventually). This is because so much less was known about it. Think of when you were a very small child. The world around you seemed so simple in comparison to the world as you know it now.

Early physicists questioned the world around them and attempted to develop mathematical models (theories) to explain and predict how objects in the world interacted. These objects were eventually said to consist of Matter.

Matter has had variations in definition over the years as well as when applied to various fields of study. However, for our current purposes:

• Matter: Anything that has Mass and Volume
  
• Volume: The amount of three-dimensional space a substance (solid, liquid, gas, or plasma) or shape occupies or contains
  
• Mass: Ability to resist motion when acted on by a Force due to the quantity of material in the object
  

Question: So what has Matter?

Answer: Everything around us!

Examples:

1. You are made of matter
   
2. Your car is made of matter
   
3. The Earth is made of matter
   
4. Pumpkin pie is made of matter
   

Question: What is the relationship of Volume to Matter?

Answer: Volume is a measurement of the space occupied by an object. Volume is used to determine the Density of an object. Density tells us how tightly crammed together matter is. Density has many properties that assist us in our analysis of the world.

Examples:

1. Wood is generally used for boats because it floats in water. This is because wood is less dense than water.
   
2. If we want a balloon to rise it is important to fill it with a less dense gas than air such as helium
   
3. Given the volume of an object, the density will give us the mass. This is because the formula for density = mass / volume
   

Question: How does mass resist motion when acted on by a force? What is mass?

Answer: Mass is the amount of material or matter an object is made up of. Mass is the measure of heftiness of the material of an object. Therefore, think of kicking a balloon. The balloon does not resist moving due to the implied kick of your boot. This is because the balloon does not contain much mass. However, if you kick a rock the same size as the balloon it will not move nearly as much. This is because the rock has a much greater mass.

Mass has no direction. To measure mass on earth we need special tools. An easy method to calculate mass without special instruments would be to calculate weight. Weight is the gravitational pull on an amount of mass.

If we weigh two items on earth (under the same gravitational pull), the more massive object will always weigh more.

Another way to measure mass would be to use a triple-balance beam scale

The usual symbol for Mass is m and its unit of measurement is the Gram (g).

In the next post we will make like the Jedi's and use the Force!