Electromagnetic Energy Topic 5 Energy in Earth Processes
energy The ability to do work The ability to do work
Electromagnetic energy The type of energy given off in transverse waves by all matter above absolute zero The type of energy given off in transverse waves by all matter above absolute zero Each kind of e-mag energy has its own wavelength Each kind of e-mag energy has its own wavelength
wavelength
Electromagnetic spectrum A model showing all the forms of e-mag energy A model showing all the forms of e-mag energy
Page 14 ESRT Page 14 ESRT Visible light can be broken down into colors by wavelength. Visible light can be broken down into colors by wavelength.
The hotter the object the more e-mag energy it gives off. Temperature of Object cold hot Amount of e-mag energy given off high low
The hotter the object, the shorter the wavelength given off. Temperature of Object cold hot Wavelength long short
E-mag waves can be refractedscatteredabsorbed reflected transmitted
The characteristics of a surface determine the amount and kind of e-mag energy absorbed. Color - dark absorb more/reflect less Color - dark absorb more/reflect less Texture (rough/smooth) - rough absorbs more Texture (rough/smooth) - rough absorbs more Luster/reflectivity (shiny/dull) - dull absorbs more Luster/reflectivity (shiny/dull) - dull absorbs more
source Region with a higher concentration of energy than its surroundings Region with a higher concentration of energy than its surroundings
Sink (no, not the kitchen kind) Region with a lower energy concentration than its surroundings Region with a lower energy concentration than its surroundings Energy always flows from a source to sink. Energy always flows from a source to sink.
* Energy is transferred across interfaces. 50°C30°C source sink The source radiates more than it absorbs. *temperature decreases* The sink absorbs more than it radiates. *temperature increases*
* Energy is transferred across interfaces. The 2 objects absorb the same amount that they radiate. *temperature is constant* This is called dynamic equilibrium or radiative balance. 40°C
Energy Transformations When e-mag energy of short wavelength is absorbed, it can be reradiated at longer wavelengths. When e-mag energy of short wavelength is absorbed, it can be reradiated at longer wavelengths. A material that is a good absorber of electromagnetic energy is a good radiator of electromagnetic energy. A material that is a good absorber of electromagnetic energy is a good radiator of electromagnetic energy.