Physics concepts and principles

Physics

The heat engine or heat pump moves heat from one location to another. It usually takes heat out of the air or from the ground and transfers it to a building, such as a house or office. The word "heat" means thermal energy not temperature. Rather than warming the house or office with a furnace that burns fuel, the heat is transferred from the air or ground by using this pump. The heat pump uses a chemical substance or machine to work. Heat pumps can be used for making spaces warmer or cooler. For example, air-to-air pumps use electricity to move heat. By doing so, a cool area becomes cooler and a warm area becomes warmer. In the cooler seasons of fall and winter, these heat pumps warm the inside of the homes. In the summer months, they transfer air that cools the buildings.

A vibration in an item creates sound waves. The waves then move outward and make the surrounding solid, gas or liquid vibrate. For example, when the skin of a drum is hit with a stick, the skin vibrates, or moves up and down, many times per second. This pushes the air surrounding the drum to make sound waves that are picked up by the human ear.

Electricity is related to charges of electrons and protons in the billions of atoms in the environment. The amount of the charge is equal for each particle, but the sign is the opposite. Electrons, orbiting outside of the nucleus, hold a negative charge; protons, in the center or nucleus of the atom, hold a positive charge. The protons are located in the center of the atom, concentrated in a small area called the nucleus. Electricity occurs because the protons cannot escape and the electrons are continually moving. There are numerous items that are electrified. In a kitchen, for example, there may be electric lights, small and large appliances, and floor cleaners.

Energy is transported through waves, such as sound waves. Electromagnetic is another form of these waves. Light is an example of an electromagnetic wave. Other electromagnetic waves include the microwaves in a microwave oven and radio waves and TV waves transmitted from broadcast stations. Waves look like the waves in an ocean, going up and down. The top is called the crest. These electromagnetic waves are different in wavelength, or the distance between one wave crest to the next.