What is Energy? Lecture 12.3 Aurora borealis

Energy Energy is ability to do work Energy is ability to do work Work is the transfer of energy to move matter. Work is the transfer of energy to move matter. Energy is measured in joules Energy is measured in joules

The 2 categories of Energy Potential energy: stored energy Potential energy: stored energy Kinetic energy: energy due to motion Kinetic energy: energy due to motion Energy is continually transferred back & forth from potential to kinetic. Energy is continually transferred back & forth from potential to kinetic. Pair share: A tell B if a rock on the top of a hill has potential or kinetic energy & what you can do to transform it into the other form.

Energy has many forms The movement of atoms is kinetic energy The movement of atoms is kinetic energy –The faster the atoms move the warmer it is  This is thermal energy Chemical energy is stored in chemical bonds & released when bonds are broken Chemical energy is stored in chemical bonds & released when bonds are broken Pair share: B tell A what 2 kinds of energy, other than chemical energy, is shown in the middle picture.

Nuclear energy Nuclear fusion- when atoms merge to form larger atoms Nuclear fusion- when atoms merge to form larger atoms –On the sun 2 H become He Nuclear fission- when large atomic nuclei are split into smaller elements Nuclear fission- when large atomic nuclei are split into smaller elements

Electricity & light Electricity – is the flow of charged particles. Electricity – is the flow of charged particles. Light – travels in electromagnetic waves Light – travels in electromagnetic waves Whiteboard: There is another kind of energy associated with lighting that you can’t see. What is it and how do you know it is there?

Conservation of Energy Energy can not be created or destroyed. It can only change form…. Energy can not be created or destroyed. It can only change form…. Think of how energy changes: Think of how energy changes: –Sun  earth  a plant  an insect flying

Review 1. Energy is the ability to do ________. 2. What kind of energy fuels the sun? 3. Electrical energy is the movement of ______ ____.

Summary Describe how energy from fusion in the sun can be transferred to become chemical energy use to fuel a car. What steps would be involved and how might the energy continue to be transferred? Describe how energy from fusion in the sun can be transferred to become chemical energy use to fuel a car. What steps would be involved and how might the energy continue to be transferred?