Chapter Six  Section 1 Section 1  Section2 Section2  Section 3 Section 3  Section 4 Section 4  Section 5 Section 5  Section 6 Section 6  Section 7 Section 7  Formulas Formulas

Section 1  A system has energy whenever it has the ability to do work, the bringing about of external or internal changes.  Object A does work on Object B if A exerts a force on B while B moves in the direction of that force. Chapter Six Home

Section 2  Raised objects and moving objects have the ability to do work.  Work is stored in an object as it is raised.  Raised objects have gravitational energy.  Moving objects have kinetic energy. Chapter Six Home

Section 3  Energy of an object is defined by how much work it can do.  Energy and work are both measured in Joules.  Energy can be transformed, but never destroyed. Chapter Six Home

Section 4  There are many forms of energy:  Kinetic Energy  Gravitational Energy  Elastic Energy  Thermal Energy  Electromagnetic Energy  Radiant Energy  Chemical Energy  Nuclear Energy Chapter Six Home

Section 5  Law of Conservation of Energy:  The total energy of all the participants in any process remains unchanged throughout that process. That is, energy cannot be created or destroyed. Energy can be transformed ( changed from one form to another), but the total amount always stays the same.  The Work-Energy Principle  Work is an energy transfer. Work reduces the energy of the system doing the work and increases the energy of the system on which work is done, both by an amount equal to the work done. Chapter Six Home

Section 6  4200 J of work raises the temperature of 1 kilogram of water by 1° Celsius. This is known as a Calorie.  Energy Efficiency of any energy transformation is the fraction of the input that appears as useful output.

Section 7  Power is the amount of work done per second (work done over the time to do it).  Power is measured in Joules per second (J/s), also known as a watt (W).

Formulas  Work = Force x Distance = Fd  Gravitational Energy = Weight x Height  Kinetic Energy = ½ Mass x Object’s Speed 2  Energy Efficiency = (Useful Output Energy) (Total Input Energy)  Power = Work Done/Time to Do It  1 Kilowatt Hour = 1000 J/s x 3600 s