Chapter 7: Ashes to Ashes - Things we Know

The things we know about the universe and the laws of physics are quit interesting and happen all around us at all times yet we often fail to see them in action. Friction for instance is a force that causes a resistance in the direction of motion of an object (kinetic), or keeps things from moving in the first place (static). Friction is one of the understood aspects of physics that we can apply laws to such as the law of conservation of energy. When there is friction in a system, some kinetic energy is converted into heat through the contact of the two surfaces. Other physics related things that we know exist are the inverse square law that describes how many things in physics including sound intensity work. In this case, the inverse square law states that the sound intensity is inversely proportional to the radius or distance from the sound source. Other things that have been proven include the Doppler effect, as discussed in chapter 1, and Sir Isaac Newton’s 3 laws of motion. The first being, all objects at rest remain at rest and all objects in motion continue in motion unless and external force is acting upon it; the second is the acceleration of an object is inversely proportional to its mass and the third is every action has an equal and opposite reaction. Essentially this chapter is nice simple review of what we have learned up to this point in physics with the exception of a few ideas that were a bit over my head and not formally introduced.