Energy in Earth Energy in Earth ProcessesProcesses

It’s All About WorkIt’s All About Work

EnergyEnergy

The ability to do work.The ability to do work. Everything that is done in the Everything that is done in the

universe involves the use or transfer universe involves the use or transfer of energy.of energy.

***Energy from the sun drives most ***Energy from the sun drives most Earth surface processes.***Earth surface processes.***

Electromagnetic EnergyElectromagnetic Energy

Transverse waves radiated by the Transverse waves radiated by the sun.sun.

Transverse waves vibrate at right Transverse waves vibrate at right angles to the direction of movement.angles to the direction of movement.

Most familiar is visible light.Most familiar is visible light. ***Different types distinguished by ***Different types distinguished by

wavelength.***wavelength.*** See page 14 of ESRT.See page 14 of ESRT.

Electromagnetic SpectrumElectromagnetic Spectrum

Microwaves

Electromagnetic SpectrumElectromagnetic Spectrum

On the chart – Longer wavelength to On the chart – Longer wavelength to the right, shorter wavelength to the the right, shorter wavelength to the left.left.

***Visible light is the only part that ***Visible light is the only part that can be seen with the human eye.***can be seen with the human eye.***

***Heat is given off as infrared ***Heat is given off as infrared radiation.***radiation.***

What happens when What happens when electromagnetic energy comes electromagnetic energy comes

in contact with a material?in contact with a material?

It can be It can be refracted or refracted or bent.bent.

The direction of The direction of the waves are the waves are changed.changed.

It can be reflected or bounced off.It can be reflected or bounced off.

Transmitted or passed through.Transmitted or passed through.

Absorbed or taken into the material.Absorbed or taken into the material.– Dark colors absorb more than light colors.Dark colors absorb more than light colors.– Rough texture absorbs more than smooth.Rough texture absorbs more than smooth.– ***Thus, dark, rough objects are the best ***Thus, dark, rough objects are the best

absorbers of the sun’s energy.***absorbers of the sun’s energy.***

Energy TransferEnergy Transfer

Energy (heat) moves from an area of Energy (heat) moves from an area of high concentration (source) to an high concentration (source) to an area of low concentration (sink).area of low concentration (sink).

This will continue until the energy This will continue until the energy between the source and the sink are between the source and the sink are even (dynamic equilibrium).even (dynamic equilibrium).

3 Methods of Transfer3 Methods of Transfer Conduction, convection and radiationConduction, convection and radiation

Conduction – transfer of heat energy from Conduction – transfer of heat energy from atom to atom or molecule to molecule. Ex. atom to atom or molecule to molecule. Ex. Hot pot handle.Hot pot handle.

Convection – transfer of heat by Convection – transfer of heat by movement in fluids, liquids and gasses. movement in fluids, liquids and gasses. Convection currents transfer heat Convection currents transfer heat throughout Earth’s atmosphere, throughout Earth’s atmosphere, hydrosphere and mantle. Ex. Smoke rising hydrosphere and mantle. Ex. Smoke rising from a campfire.from a campfire.

Radiation – heat transferred via Radiation – heat transferred via electromagnetic waves. Can go across electromagnetic waves. Can go across empty space. Fastest – travels at the empty space. Fastest – travels at the speed of light.speed of light.

Heat & TemperatureHeat & Temperature Temperature – average kinetic energy of Temperature – average kinetic energy of

particles in a substance.particles in a substance. Heat – total kinetic energy of particles in a Heat – total kinetic energy of particles in a

substance.substance. Heat always flows from higher energy to Heat always flows from higher energy to

lower energy.lower energy.

CalorieCalorie

Different substances heat up at Different substances heat up at different rates. different rates.

Unit for measuring heat quantity is Unit for measuring heat quantity is the calorie.the calorie.

Defined as the quantity of heat Defined as the quantity of heat needed to raise the temperature of 1 needed to raise the temperature of 1 gram of water 1 degree Celsius.gram of water 1 degree Celsius.

Specific HeatSpecific Heat

The quantity of heat required to raise The quantity of heat required to raise the temperature of 1 gram of a the temperature of 1 gram of a substance 1 degree Celsius.substance 1 degree Celsius.

Every substance has its own specific Every substance has its own specific heat, and it is different from all other heat, and it is different from all other substances.substances.

Liquid water is the highest at 1.0 Liquid water is the highest at 1.0 cal/gcal/gooC.C.

Page 1 ESRT.Page 1 ESRT.

In simple terms specific heat is the In simple terms specific heat is the resistance of a substance to heating resistance of a substance to heating up or cooling off.up or cooling off.

***Large bodies of water have a ***Large bodies of water have a major moderating effect on weather major moderating effect on weather and climate because water has the and climate because water has the highest specific heat of any natural highest specific heat of any natural substance.***substance.***

Heat Energy and Changes of Heat Energy and Changes of StateState

Melting – solid to liquid Melting – solid to liquid Solidification or freezing – liquid to Solidification or freezing – liquid to

solid solid Evaporation or vaporization – liquid Evaporation or vaporization – liquid

to gasto gas Condensation – gas to liquidCondensation – gas to liquid Sublimation – solid to gasSublimation – solid to gas

Stored Heat and Changes of Stored Heat and Changes of StateState

When a material is in one of the 3 When a material is in one of the 3 states, its temperature rises as heat states, its temperature rises as heat is added to it.is added to it.

If the material is in the process of If the material is in the process of changing state, its temperature changing state, its temperature remains the same.remains the same.