energy

Energy Physical ScienceNature of Energy Energy is all around you. • You hear energy as sound, you see energy as light, you can feel energy in wind. • Living organisms need energy for growth and movement. • You use energy when you hit a tennis ball, compress a spring, or lift a grocery bag. • Energy is the ability to do work. Brainstorm other types of energy that surrounds us…Energy • The energy released by a supernova is capable of destroying a nearby solar system in just a few hours. A supernova is one of the greatest concentrations of energy in the universe. Try to find a United streaming video of a supernova – this would be cool on this slide… Forms of Energy • Energy appears in many forms. There are five main forms of energy. • Mechanical • Heat • Chemical • Electromagnetic • Nuclear See if the students can name the forms first – then click through… Mechanical Energy Energy of motion. Examples: • Water in a waterfall • Wind • Moving vehicles • Sound • Blood traveling through your body Other examples from the class???Heat Energy • The internal motion of atoms. • The faster the molecules move, the more heat energy is produced. Examples: Friction Changes in state of matter Discuss common kinds of friction students may be familiar with – hands rubbing together – tires-engine parts Candles – One lit candle in a car can increase the temp 2 degrees – if you are in a snow bank and cannot run the heater… Chemical Energy • Energy that exists in the bonds that hold atoms together. • When bonds are broken, chemical energy is released. Examples: • Digesting food…bonds are broken to release energy for your body to store and use. • Sports… your body uses energy stored in your muscles obtained from food. • Fire–a chemical change. Sodium metal reacts with water. Remind students of video of the sodium metal in water – produced fire – Chemical Change…Electromagnetic Energy Moving electric charges. Examples: • Power lines carry electricity • Electric motors are driven by electromagnetic energy • Light is this form of energy (X-rays, radio waves, laser light etc.) Explain the picture with the xrays…Nuclear Energy • When the nucleus of an atom splits, nuclear energy is released. • Nuclear energy is the most concentrated form of energy. • Fission/fusion What is the difference between fission and fusion? Which one is/was being used in this state?10 Questions • What is energy? • Can energy be transferred from one object to another? • What are the different forms of energy? 1. The ability to do work 2. Yes, when an object does work on another object – energy gets transferred. 3. Heat, mechanical, electromagnetic, nuclear, and chemical.11 States of Energy There are two states of energy: Potential and Kinetic12 Potential Energy • Stored energy – energy of position. • Not always mechanical energy – can be other forms. • Gravitational Potential energy – dependent on height and weight. • GPE = Weight x Height • Units – Newton*meter13 Kinetic Energy • The energy of motion. • The faster the object moves – the more kinetic energy. • Kinetic energy depends on both mass and velocity. • KE = ½(mass x velocity2) • Kg m2/s2 =Newton*meter= Joules Energy is the ability to do work – so the units are the same for energy as they are for work. -JOULES14 Energy Conversions • The most common energy conversion involves the changing of potential energy into kinetic energy or vice-versa. Examples: Ball thrown in the air Roller coaster Watch the animation and explain how this is a simple version of potential and kinetic energy exchange-it doesn’t take into consideration air resistance and friction – heat energy conversion for the friction and air resistance.15 More Conversions • All forms of energy can be converted to other forms. • Law of Conservation of Energy: Energy cannot be created or destroyed. • Einstein – If matter is destroyed, energy is created, if energy is destroyed, matter is created. The total amount of mass and energy is conserved. Electromagnetic energy comes in…produces light then, converted to heat.. Electrical energy is converted to electromagnetic and heat energy. 16 Is energy that is ... Formula Energy of... Formula Ability to do... Types of Energy Kinetic Can be ? ? ? ? ? 1. ? 2. 3. 4. 5. Concept Review Heat Chemical Nuclear Mechanical Electromagnetic Work Potential Stored Weight X Height Motion 1/2mv2 Click for the answers… 17 Writing Assignment • Identify the various energy conversions involved in the following events: • An object is raised and then allowed to fall. As it hits the ground it stops, produces a sound and becomes warmer. • Due tomorrow at the beginning of class. Page 407 # 4 Demonstrate a book falling to ground.18 Resources Roller coaster Animation: http://www.glenbrook.k12.il.us/gbssci/phys/mmedia/energy/ce.html Mouse Trap animation http://communities.msn.com/VickisClipArtandAnimationStorage/mimichar.msnw?action=ShowPhoto&PhotoID=4571 Chevy animation http://communities.msn.com/VickisClipArtandAnimationStorage/angelfirepics.msnw?action=ShowPhoto&PhotoID=4601 Pics http://www.glenbrook.k12.il.us/gbssci/phys/Class/energy/u5l1e.html http://www.glenbrook.k12.il.us/gbssci/phys/Class/energy/u5l1b.html http://www.glenbrook.k12.il.us/gbssci/phys/Class/energy/u5l1d.html http://library.thinkquest.org/20331/types/http://library.thinkquest.org/20331/history/timeline1600.html http://library.thinkquest.org/20331/history/timeline1900.html http://library.thinkquest.org/2745/data/loops.htm http://www.sunybroome.edu/~eet_dept/POWERPIX.html http://www.st-agnes.org/~lstinson/webpages/kinpot.htm http://www.rz.uni-frankfurt.de/~schauder/http://radar.metr.ou.edu/OK1/meteorology/HeatTransfer.html http://hrast.pef.uni-lj.si/docs/en/web-based_education/infodist/tutorial/simulate/off.htm http://heritage.stsci.edu/2000/15/index.html http://csep10.phys.utk.edu/guidry/violence/remnants-save.html Text Exploring Physical Science, Prentice Hall, chapter 16.