ENERGY

Energy –Changes in technology have depended in large part on this resource –History --- Human & animal muscle, moving wind and falling water –Coal and oil became new energy sources during industrial revolution --- glass factories, steel mills –Many of today’s factories use electricity only. They do not need to be near the energy source

Energy  Work –Work is done on an object when a force pushes or pulls on an object, causing it to move --- W = F  d –Units are N-m or Joules, foot-pounds  Energy –It is the ability to do work. –Today’s technology concerns changing energy from one form into another for some useful work –Kinetic energy is the energy an object has because of its motion –Potential energy is energy that is stored in an object because of its position, shape, or some other features –Potential energy can be changed into kinetic energy --- examples –Conservation of energy --- Energy can not be created or destroyed, but it can be changed from one form to another

Energy  Energy in Modern Society  Lightening  Heating  Transportation  Telephones  Construction  Manufacturing  Farming –Energy sources can be described as limited, unlimited, or renewable

Limited Energy Sources  Fossil Fuels –They come from the remains of plants and animals that lived millions of years ago --- oil, natural gas and coal –Molecules are two or more atoms joined together with high energy bonds –The break down of molecules releases much of the energy in the high-energy bonds –The changes that take place during the burning of fuels are called chemical changes –Energy from the burning of fuel is sometimes called chemical energy –Coal  Coal was one of the first fossil fuels  Coal can be mined from the surface of the land by strip mining  Coal has now been replaced by oil, gas, and electricity  After the coal has burned, smoke can be cleaned by scrubbers

Limited Energy Sources  Fossil Fuels –Oil  About half of the energy we use comes from oil  It is much more easily taken, stored and transported as compared to coal –Natural Gas  Used for home heating and cooking  Also used as a fuel in glass industry  Other forms or fuels --- home heating oil, diesel fuel, gasoline, jet fuel –Oil and gas form only at right combination of rock types and structures –People searching for these fuels use magnetometers and seismographs