Energy Energy – is defined as the ability to do work; the ability to cause change; all energy can be transferred Two main types of Energy: Kinetic Energy: Is the energy an object has due to its motion Potential Energy: Is energy stored in an object due to its position (the higher you are…) See Handout Mechanical Energy The sum of the kinetic and potential energy of an object is the mechanical energy of the object.

Thermal Energy Is the sum of the kinetic and potential energy of a the particles in an object due to their motion; transfer of heat; energy of hot objects 3 Ways: Conduction, Convection, Radiation It all has to do with HEAT & Temperature Temperature: is the measure of the average kinetic energy of the particles in a material Connection: The temperature of a material increase as the thermal energy of the material increases!

Energies Chemical Energy Electromagnetic Energy When you are eating you are providing your body with energy…but how does your body convert a burger into body fuel (energy) The chemical compounds in food contain molecules In these molecules there is energy When your stomach breaks down your burger it breaks the molecule bonds and releases energy Chemical energy: is the energy stored between bonds; it’s a kind of potential energy b/c it’s waiting to be released or split apart; it is released when chemical reactions occur. Is energy that travels in waves, like the sun Includes: Radio waves, microwaves, light and X-rays (electromagnetic)

Energies Electrical Energy Nuclear Energy Is energy that is carried by an electric current ALL electrical appliances convert electrical energy into other forms of energy It occurs when electrons are released (charge is changed….and a BOND takes energy!!!) This energy begins at the very center of an atom – its NUCLEUS Nuclear Energy is energy that is stored in the nucleus of an atom It is released when a change occurs – nuclei can be joined together (like in the sun, forming fusion) or split apart (like in a nuclear power plant where uranium atoms are split apart called nuclear fission) – the energy from this is used to produce electrical energy

Measuring Energy In the SI system of units, energy is measured using a unit called the joule (J). Another unit for energy is the calorie. One calorie is the amount of energy needed to warm one gram of water by 1°C A different energy unit is used to measure the energy content of food. Calorie.

The LAW! Law of Conservation of Energy -> Energy can’t be created nor destroyed; It Flows or is Converted/Transferred It FLOWS throughout environment between Biotic and Abiotic factors (Biotic – Living things; Abiotic – non living things that interact in the environment) HOW??? As it flows through; it transforms into different kinds of energy Examples: Photosynthesis- Light energy is transferred into chemical

Energy Flow Energy flows through our environment as it is converted from one form to another. It also flows when it is transferred from one organisms to another.

Food Chains A food chain is a way of showing how energy and matter can be passed or transferred from one organisms to another.

Energy Pyramid Food chains and food webs have different levels of organisms depending on one another in an ecosystem. As producers get eaten by consumers, energy and matter is transferred from on organism to the other in that ecosystem. An energy pyramid is the amount of energy available at each feeding level in an ecosystem.

Transformers! Energy is continually changing from one form to another. These changes from one energy form to another are called transformations. The total amount of energy you have before it changes will be the same as the energy you have afterwards it will just be in different forms Ex. When you ride a bike you are transforming chemical energy to kinetic energy. Chemical energy is also transformed into thermal energy and you feel hotter. Thermal energy is ALWAYS produced when energy changes

Transforming Examples Kinetic to Potential -> Paper Ball Thermal Energy -> Conduction, Convection, Radiation Thermal -> Mechanical -> Chemical -> Thermal: A Car, p289 Potential to Chemical to Kinetic -> Big Mac! Yum! Electrical to Mechanical to thermal -> A Fan, p291 Nuclear to Thermal and more -> Stars, p292

Worn out Energy! The more you use or convert something, the more worn out it gets… When energy is changed from one form to another, it becomes less concentrated and more spread out. Energy that does work is Usable & is Organized Energy that is not usable is called Waste Energy & is Disorganized Example: When the flashlight is used, the light and thermal energy produced is transferred to the air surrounding the flashlight The more we use it the less “usable “ it is…WHY?

WHY? Disorder & Entropy The amount of disorganized energy in the universe is always increasing Therefore, the more we use the energy and it spreads out, the more disorganized (waste) it becomes We measure this through ENTROPY The “entropy” of a system is a measure of the disorder, p. 291 – “Entropy always Increases”

Conserving Energy Nonrenewable Resources- Can NOT be replaced by natural processes in less than 100 years; Ex: Fossil Fuels (is an energy resource from buried remains of ancient plants and dead stuff – we use it to generate electricity) Renewable Resources – resources that can be recycled or replaced by natural processes in less than 100 years Burning of Fossil Fuels – Electricity, Gas, Heat, etc. Global Warming Greenhouse Effect What do we do? Alternative Forms of Energy!

Alternative Forms of Energy Solar Energy Wind Energy Energy that comes from the sun! Solar cells actively collect energy from the sun and transform it into electricity Is clean and inexhaustible energy Disadvantages: Cloudy days Storage Worn out batteries Wind is air in motion Wind energy is converted into electricity

Alternative Forms of Energy Hydropower Dams & their workings Water packs a hefty punch! It is harnessed through Dams Water doesn’t work alone: Solar energy heats water on the surface, causing it to evaporate. This water vapor condenses into clouds and falls back onto the surface as precipitation (rain, snow, etc.). The water flows through rivers back into the oceans, where it can evaporate and begin the cycle over again.

Alternate Forms of Energy Geothermal Biomass The word geothermal comes from the Greek words geo (earth) and therme (heat). Geothermal energy is heat from within the Earth. We can recover this heat as steam or hot water and use it to heat buildings or generate electricity. Examples: Volcanoes, Hot springs, Geysers is organic material made from plants and animals. Biomass contains stored energy from the sun.  Plants absorb the sun's energy in a process called photosynthesis. The chemical energy in plants gets passed on to animals and people that eat them. When burned, the chemical energy in biomass is released as heat. Can be used as fuel, heat, biomethane, or methane gases