Chapter 13Chapter 13

Energy

Chapter 13

13.1 What is Energy13.1 What is Energy Energy - The ability to do work or cause

change (such as moving an object some distance)

Work is the transfer of energy. Energy is measured in Joules Power is the rate at which energy is

transferred (converted from one form to another) or the amount of energy transferred in a unit of time.

13.1 What is Energy13.1 What is Energy Power = Energy transferred / Time Review

Power - The rate at which work is donepower = work/time power = force x distance/time power units = J/sec = Watts (W)

Chapter 13

13.1 What is Energy13.1 What is Energy Two basic kinds of energy: kinetic energy and

potential energy Kinetic energy (KE) - energy of motion

(kinetos) KE = 1/2 mass x velocity2

Potential energy (PE) - stored energy due to position or shape of an object (gravitational or spring)

Gravitational Potential Energy = work done to lift the object

Chapter 13

13.1 What is Energy13.1 What is Energy

Remember: Work = Force X Distance Gravitational potential energy =

Weight X Height (Weight is a Force = Mass X Acceleration) Therefore PEG = mass x acceleration due to

gravity (9.8 m/sec2) x height Elastic potential energy – Energy associated

with objects that are stretched or compressed

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Chapter 13

13.2 Forms of Energy13.2 Forms of Energy

Mechanical Energy – The form of energy associated with the position and motion of an object

Mechanical Energy = Potential energy + Kinetic energy

13.2 Forms of Energy13.2 Forms of Energy

Forms of energy associated with the particles of objects include thermal energy, electrical energy, chemical energy, nuclear energy, and electromagnetic energy.

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13.2 Forms of Energy13.2 Forms of Energy

Thermal energy – heat – The total potential and kinetic energy of the particles in an object

Electrical energy – electricity – The energy of electric charges

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13.2 Forms of Energy13.2 Forms of Energy

Chemical energy - chemical reaction/bonds – The potential energy stored in the chemical bonds that hold compounds together

Nuclear energy – fission & fusion – The potential energy stored in the nucleus of an atom

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13.2 Forms of Energy13.2 Forms of Energy

Electromagnetic energy - light, radiation – Travels in waves which have some electrical and magnetic properties

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Chapter 13

13.3 Energy Transformations and Conservation13.3 Energy Transformations and Conservation Most forms of energy can be transformed into

other forms. energy transformation- the process of

changing one form of energy into another One of the most common energy

transformations is the transformation between potential energy and kinetic energy.

body - convert chemical energy in food to mechanical energy to move musclesmatch - mechanical thermal chemical thermal lightBook examples - waterfall, juggling, pole vault, pendulum

The law of conservation of energy – According to the law of conservation of energy, energy cannot be created or destroyed. The total amount of energy is the same before and after any transformation.

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Chapter 13

friction -friction -

converts mechanical to thermal energy, reduces efficiency

Energy and Matter -Energy and Matter -

Einstein’s theory of relativityMatter can be transformed to energy.Matter is anything that has mass and

takes up space.Therefore, matter and energy together

are always conserved.

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Chapter 13

13.4 Energy conversions and fossil fuels13.4 Energy conversions and fossil fuels

Formed from the remains of ancient plants and animals that lived 400 million years ago.

Coal, petroleum, natural gas - chemical potential energy

Fossil fuels - contain energy that came from the sun.

Energy conversions pg. 464 – Flowchart

13.4 Energy conversions and fossil fuels13.4 Energy conversions and fossil fuels

Fossil fuels can be burned to release the (potential) chemical energy stored millions of years ago.

Combustion – The process of burning fuels

Non-Renewable Energy

Chapter 13

Chapter 13

Chapter 13 VocabularyChapter 13 Vocabulary Energy Kinetic energy Potential energy Gravitational potential energy Elastic potential energy Mechanical energy Thermal energy Electrical energy

Chapter 13 VocabularyChapter 13 Vocabulary Chemical energy Nuclear Energy Electromagnetic energy Energy transformation Law of conservation of energy Matter Fossil fuels Combustion

Chapter 13