Geography 1900 Lecture 6

Front 1

energy

Back 1

capacity for doing work

Front 2

work

Back 2

process of exerting a force upon matter and moving it a distance

m x a x d= work

Front 3

kintetic energy

Back 3

energy of motion; a funciton of the object's weight and speed

Front 4

potential energy

Back 4

energy in reserve or storage

Front 5

physical or "real world" energy- MECHANICAL ENERGY

Back 5

kinetic form: flowing water, wind, falling rocks, moving cars, walking
storage form: energy of position. it's a function of weight adn elevation above sea level for visible objects and air

Front 6

Internal energy at the molecule level

Back 6

k.e. form is thermal energy: speed of molecular motion
all these motions determine an object's temp and energy content
p.e. form: only occurs in water on earth, through water's "state"
solids: molecules vibrate
liquids: molecules also rotate

Front 7

chemical energy

Back 7

p.e.= energy stored in leaves, food, and photosynthesis
k.e.= burning of carbohydrate, plants, trees, gasoline oil

Front 8

radiation

Back 8

Energy in the form of electromagnetic waves emitted by every object in the universe

Front 9

joule

Back 9

Joule: unit of measurement for energy.

Front 10

calories

Back 10

old fashioned units used in physics

Front 11

electrical energy

Back 11

involving electrons and protons

Front 12

atomic/nuclear

Back 12

nuclei of atoms, radioactive decay of such

Front 13

law of conservation of energy

Back 13

energy cannot be created or destroyed, only transformed form one form to another

Front 14

plate tectonics

Back 14

nuclear energ>kinetic internal energy> mechanical kinetic energy>sensible heat

Front 15

coal for electricity in a light bulb

Back 15

Radiant (solar) → Chemical (photosynthesis) → Chemical (respiration) → Electrical → Radiant (light 10%) (+ sensible heat 90%)

Front 16

energy transformations- automobile

in the atmosphere

Back 16

Automobile: Electrical → Chemical (respiration) → Mechanical kinetic → sensible Heat

atmosphere:Radiant (solar) → kinetic internal energy (air warms up, sensible heat) + Latent Heat (evaporates water) → Mechanical potential energy (atmosphere expands vertically against the pull of gravity)

Front 17

power

Back 17

flow of energy, measured in watts

one watt= one joule/second

Front 18

heat: energy transfer across objects or between objects

Back 18

• Some matter is hotter in one place than another. – e.g.: air in a room; across an iron bar; water in swim
pool, Equator vs North Pole
• Some matter is hotter than other nearby matter
– Hot ground, cold air; hot stove, cold pot of water;

Front 19

heat

Back 19

energy in the process of being transferred due to temperature differences between objects

Front 20

conduction

Back 20

transfer of heat in solids, molecule to molecule

Front 21

convection

Back 21

transfer of heat in liquids and gases

Front 22

radiation

Back 22

transfer of heat, the electromagnetic waves themselves moves aroudn to redistribute temperature

Front 23

sensible heat

Back 23

energy transfer, due to temp differences, measured w/ thermometer or felt by human skin

Front 24

latent heat

Back 24

energy transfer due to temp differences is associated with changes in the "state" of water

Front 25

mechanisms of heat transfer

Back 25

sensible and latent heat transfer is only done by conduction and convection, which transfer these heats by movement

Front 26

radiant energy transfer

Back 26

• Emitted as electromagnetic radiation waves
• Emitted by all objects in the universe
• Requires no physical mechanism to move
• Moves in the vacuum of space
• Always travels at a constant speed 300,000 km/sec (186,000 mi/sec), of light.

Front 27

electromagnetic spectrum

Back 27

radiant energhy consists of a spectrum of electrical and magnetic waves of varying wavelengths adn intensities

Front 28

stefan boltzmann law

Back 28

amount of electromagnetic energy emitted by an object is proportional to its temperature
hotter objects emit more radiant energy than cooler ones

Front 29

planck's law

Back 29

defines how the energy is distributed by wavelength
(unevenly)

Front 30

wien's law

Back 30

hotter objects radiate at shorter wavelenth than cooler bodies

Front 31

inverse squares law

Back 31

intensity of radiation falling on a planet is reduced by the square of the distance of the planet from the sun