Transcript Heat
The ability to do work Unit: the Joule (also calorie & Btu) http://www.energyquest.ca.gov/story/chapter01.html • Energy flows from High(H) to Low(L) – From source to sink – Ex: temp, pressure, elevation – Differences in air pressure cause wind! But what is the source of all this energy? States of Energy • Kinetic (KE) – energy of motion – example: roller coaster moving fast, mill river flowing down to bay • Potential (PE) – Stored energy – Energy of position Example: roller coaster at top, rock on hill, Battery, food Can an object have KE and PE at the same time? How are these energies similar? Different? What is the difference between heat and temperature? • Temperature • - measure of average KE of particles • Heat – Form of energy – Depends on particle motion and amount – Ex: a large pot of boiling water has much more heat than a cup of boiling water How is heat transferred from one place to another? HEAT ENERGY TRANSFER(3) 1. CONDUCTION 2. CONVECTION 3. RADIATION CONDUCTION • Transfer of energy from one particle to another through direct contact. • Works in solids, liquids and gases • Good Conductors (metals) • Good Insulators(air, glass, plastic) What happens to a materials volume and density when heated? (Thermal expansion) http://www.kangwon.ac.kr/~sericc/sci_lab/physics/conduction/conductio CONVECTION • Transfer of heat in a fluid caused by a difference in densities. • BUT HOW? • What is a fluid? (a gas or liquid) • Example: boiling water, mantle, atmosphere, hydrosphere http://www.metacafe.com/watch/898995/impressive_convection_demonstration/ m/books/earth_science/terc/content/visualizations/es1903/es1903page01.cfm Land and Sea Breeze ESRT p10 Where do you see convection currents on this picture? Why is this important? ESRT - Page 14 Convection? Where? Layers of Earth • Lithosphere – crust and upper mantle (rigid tectonic plates) • MOHO – boundary between crust and mantle • Asthenosphere –area in mantle where convection currents move plates • Outer Core – believed to be a liquid (proof from earthquake waves) • Inner Core – solid, dense http://www.ig.uit.no/~kaarek/geology_intro/earthsinterior.swf Convection • Movement of a fluid (gas/liquid) due to differences in density (ex: atmosphere, asthensosphere) http://education.sdsc.edu/optiputer/flash/convection.htm - convection sim (plates) http://earthobservatory.nasa.gov/Study/GreenRoof/greenroof.html On May 11-12, 1997, NASA used a specially outfitted Lear Jet to collect thermal data on metropolitan Atlanta, Georgia. Nicknamed “Hot-Lanta” by some of its residents, the city saw daytime air temperatures of only about 26.7 degrees Celsius (80 degrees Fahrenheit) on those days, but some of its surface temperatures soared to 47.8 degrees Celsius (118 degrees Fahrenheit). In this image, blue shows cool temperatures and red shows warm temperatures. Pockets of especially hot temperatures appear in white. (Image courtesy NASA/Goddard Space Flight Center Scientific Visualization Studio.) Green roofs can range in complexity from a shallow layer of soil and plants to more elaborate rooftop garden with trees and shrubs. The more elaborate roofs place greater structural loads on buildings and require more maintenance, so planning and implementi ng them is more complicated. This photo shows the garden-like green roof atop the Solaire in Battery Park City in New York. (Photo Copyright © birdw0rks/Simon Bird and the Albanese Organization.) RADIATION • Transfer of heat and electromagnetic energy through empty space. • The sun is the major source of energy for the earth – We call this insolation (not insulation) – The earth’s radiation is called terrestrial radiation • Absorption, Reflection, • Do cold objects give off radiation? • radiometer • http://www.classzone.com/books/earth_science/ter c/content/visualizations/es2601/es2601page01.cfm How does radiation (EM energy) interact with the Earth? REFLECT ABSORB TRANSMIT SCATTER REFRACT Vocab • Electromagnetic spectrum- radiation of all different wavelengths traveling at the speed of light (ESRT p14) • Wavelength- distance between a point on wave and the corresponding point on the next wave. (crest to crest) Reflection vs Refraction Las Vegas hotel guests severely burned after windows reflect sun to cause 'death ray' By Daily Mail Reporter Last updated at 10:00 AM on 30th September 2010 Insolation and re-radiation ESRT – page 14 VISIBLE INFRARED http://www.classzone.com/books/earth_science/terc/content/visualizations/es2802/es2802page01.cfm?chapter_no=visualization http://www.ehso.com/ehshome/cellphonecancer.php ESRT – page 15 (top) Stars Stars have • Different colors – Which indicate different temperatures The hotter a star is, the faster it burns its life away. Emission Line Hydrogen: Helium: Carbon: •http://www.colorado.edu/physics/2000/quantumzone/ http://jersey.uoregon.edu/vlab/elements/Elements.html - emission and absorption spectra – period table web.ncf.ca/jim/misc/cfl/index.html http://sci-toys.com/scitoys/scitoys/light/cd_spectroscope/annotated_spectrum.jpg http://www.bramboroson.com/astro/images/doppler_overview.jpg Doppler Effect • Objects/light moving toward have compressed waves (blue shift) • Objects/light moving away have expanding waves (red shift) •http://highered.mcgraw-hill.com/sites/0072482621/student_view0/animations.html# chap 6 –red and blue shift police car http://www.classzone.com/books/earth_science/terc/content/visualizations/es2802/es2802page01.cfm?chapter_no=visualization •http://www.astro.ubc.ca/~scharein/a311/Sim.html (big band and doppler) good one! •http://bcs.whfreeman.com/universe6e/pages/bcsmain.asp?s=00110&n=01000&i=01110.03&v=category&o=|02000|01000|&ns=0&uid=0&rau=0 http://www.wwnorton.com/college/geo/egeo/animations/ch1.htm New for 08/09 *** Doppler radar http://radar.weather.gov/ http://www.srh.noaa.gov/srh/jetstream/doppler/doppler_intro. htm http://www.srh.noaa.gov/radar/radinfo/radinfo.html docs.kde.org/.../kstars/ai-colorandtemp.html • The Electromagnetic Spectrum (EM) • Esrt 14 • http://www.colorado.edu/physics/2000/quantumzone/ (samples of spectral linez) http://www.classzone.com/books/earth_science/terc/content/visualizations/es2802/es2802page01.cfm?chapter_no=visualiz ation Observe the change in a star's spectrum as its motion changes • http://www3.interscience.wiley.com:8100/legacy/college/strahler/0471669695/animations/ch02/animation1.htm • http://www.classzone.com/books/earth_science/terc/content/investigations/es2803/es2803page01.cfm?chapter_no=in vestigation