The Four Energy Systems  Mechanical  Fluid  Electrical  Thermal

The Prime Movers of the Four Energy Systems  Mechanical - Force  Fluid- Pressure  Electrical- Voltage  Thermal- Temperature

“Work” in a Mechanical Energy System  Mechanical work happens when forces or torques cause objects to move.  Work = Force X Distance  Work = Torque X Angle

“Work” in a Fluid Energy System  In Fluid systems, work is done when a pressure difference causes liquids or gases to move.  Work = Pressure X Volume

“Work” in a Fluid Energy System  Work occurs in a fluid system when fluid pressure p causes a given volume (  v) of liquids or gases to move.  W = p X (  v)

“Work” in a Fluid Energy System  Work occurs in a fluid system when a fixed volume of fluid v moves through a pressure difference (  p).  W = (  p) X v

What is Mechanical Work? Work in a mechanical system involves two parts.  An applied force must act on an object.  The object must move while the force is applied.

What is Energy? ENERGY is the ability to do WORK  To cause something to MOVE!  ENERGY is the ability to cause Change  Living things cannot work without Energy, and machines cannot work without Energy.

What is Energy?  You cannot get no more Work out of a Machine then the ENERGY you put into it.  Due to FRICTION, the WORK produced is usually less than the Energy used.

What is Energy?  Energy cannot be created or destroyed.  Forms of ENERGY can be transferred from one form to another.  The use of Energy and the lost of Energy usually ends up as HEAT.

How do you define the amount of work being done?  The force applied in the direction of the motion of the object times the distance the object moves while the force is acting.

Name Six Simple Machines?  Lever  Pulley  Wheel & Axle  Inclined Plane  Wedge  Screw

Lever

Every Lever has three (3) parts: A. Resistance Force or Load, What you are trying to move or lift. B. Effort Force - The Work done on the Lever. C. Fulcrum – A fixed pivot point.

Three Types of Levers The position of the fulcrum in relation to the applied force determines the lever class

Three Types of Levers

Pulley

Pulley Mechanical Advantage A fixed pulley has no mechanical advantage. It only changes direction.

Pulley Mechanical Advantage A movable pulley has mechanical advantage based upon how many supporting strands.

Wheel & Axle

Incline Plane

Inclined Plane

Wedge

Screw

Open Systems In open systems, matter may flow in and out of the system boundaries. The first law of thermodynamics for open systems states: the increase in the internal energy of a system is equal to the amount of energy added to the system by matter flowing in and by heating, minus the amount lost by matter flowing out and in the form of work done by the system.

Open Systems This type of system uses wells or a body of water as the source of heat exchange fluid that circulates directly through a heat exchanger in the building. Once it has circulated through the heat exchanger, the water returns to the ground through the recharge well or the body of water.

Closed Systems A closed systems can exchange heat and work, but not matter, with it’s surroundings.

Closed Systems Closed/Pond Loop System Since water transfers heat much better than soil, closed loop systems are often located in lakes or ponds by submerging GeoExchange loop coils in the water.

Information can be found on the class web site.