HEAT

(A FORM OF ENERGY)

TRANSFER OCCURS BY

- RADIATION - HEAT TRANSFER BY

ELECTROMAGNETIC WAVES (SUNLIGHT)

IMPORTANT AT EARTH SURFACE BUT NOT VERY

EFFICIENT IN SOLID EARTH

- CONDUCTION - HEAT TRANSFER BY MOLECULES

COLLIDING (TOUCH A HOT OR COLD OBJECT)

IMPORTANT IN SOLID EARTH BUT SLOW

- CONVECTION - HEAT TRANSFER BY MOTION OF

MATERIAL (HOT AIR IS LESS DENSE THAN COLD, SO IT RISES)

IMPORTANT IN SOLID EARTH, OCEAN, AND ATMOSPHERE - MORE EFFICIENT THAN CONDUCTION

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ANALOGY: MONEY CAN BE TRANSFERRED ELECTRONICALLY (fast but easily disrupted), BY MAIL (slow), OR BY CARRYING BAGS OF CURRENCY