Presentation on theme: "Thermal Energy Transfers"— Presentation transcript:
1 Thermal Energy Transfers Chapter 6 Lessons 1 and 2
2 Thermal Energy and Temperature Sum of the kinetic energy and the potential energy of the particles that make up a materialTemperatureAverage kinetic energy of the particles that make up a material
3 Thermal Energy and Temperature continued Temperature and thermal energy are not the same!Similar kinetic energy (ice melting)Different potential energy (distance between particles)
4 HeatMovement of thermal energy from a warmer object to a cooler objectHeat and thermal energy are not the same.All objects have thermal energy.When you heat an object, thermal energy is transferred.
5 How is thermal energy transferred? Radiation, Conduction, Convection
6 RadiationThe transfer of thermal energy from one material to another by electromagnetic wavesWarm objects: more radiationCan be transferred through solids, liquids, and gasesOnly way thermal energy can travel from Sun to EarthSpace is a vacuum.
7 Radiation continued How does the Sun heat the inside of a car? Jumping Penny Demo
8 ConductionTransfer of thermal energy between materials by the collision of particles (contact)Continues until all particles in contact are equalThermal conductorsA material through which thermal energy flows easilyMetalsThermal insulatorsMaterial through which thermal energy does not flow easily
9 Conduction continued Specific Heat The amount of thermal energy required to increase the temperature of 1 kg of material by 1CThermal conductors have a lower specific heatThermal insulators have a higher specific heatWater has a high specific heatPrevents body from overheatingUsed to cool machineryPools, oceans, lakes cool in summer
10 Thermal Expansion and Contraction An increase in a material’s volume when its temperature increasesParticles speed up and move farther apartThermal ContractionA decrease in a material’s volume when its temperature decreasesParticles slow down and move closer togetherMost noticeable in gases, less in liquids, and least in solids
11 Thermal Expansion and Contraction continued Sidewalk GapsToo much expansion causes cracksControl joints cut for cracksHot Air BalloonsThermal Expansion – to riseThermal Contraction – to landOvenproof GlassExpands less than ordinary glass
12 ConvectionWarm liquid moves from one place to another, which transfers thermal energyOnly occurs in fluids (water, air, magma, syrup)
13 Density, Thermal Expansion, Thermal Contraction Heating water:Burner transfers thermal energy to the containerThermal expansion in water in the bottom makes it less denseWater surface transfers thermal energy to airWater on surface cools and contractsDense water sinks to the bottomLess dense water risesCycle continues
14 Convection Currents in Earth’s Atmosphere Convection Current: movement of fluids in a cycle because of convectionCirculates water on Earth, air in a room, materials in Earth’s interior,Moves matter and thermal energy from inside the Sun to its surfaceMove air between the equator and latitudes 30N and 30S Earth’s climatesSun’s thermal energy is concentrated in this areaHeat moves from warmer objects to cooler objects