POWER

POWER

 

Power involves converting one form of energy into another. That conversion is constantly under way. Energy from the sun is harnessed by plants through photosynthesis, and our bodies convert energy-rich carbohydrates into motion. Since prehistory, peo ple have tapped outside sources of power, such as draft ani mals, to enable them to do more work. The first non-animal power source may have been fire, with which burning wood or waste was translated into heat for warmth and cooking. ANSWER BOOK 1 CHAPTER EIGHT SCIENCE & TECH

POWER

The earliest evidence of mechanized power production dates from the first century B.C., in Greece, with the use of waterwheels. Capturing the gravity generated force of water rushing down

a stream (or on the surging tide), water wheels powered industry for centuries. grinding meal, sawing logs, weaving cloth, operating pumps, and driving the bellows in forges and furnaces.In the mountainous region be tween Iran and Afghanistan, a differ ent form of energy conversion took h root: the windmill, designed to turn the force of the wind into mechani cal work. Arabic writings in the ninth century A.D. referred to Persian millers who had fixed horizontal sails to a ver tical shaft to turn a millstone.

These early sources of power were all sustainable: They converted power into energy without consuming the original resource. But they were also limited geographically, operational only in places with a steady flow of water or a steady wind, and unpredictable to the extent that seasonal weather changes could determine available power.With the coal-burning steam en gines and harnessed electricity that made possible the industrial revolution, humankind entered the era of nonre newable resources. The focus shifted to thermal energy and the force of com bustion, whether by generated steam driving engines and turbines or by con tained explosions driving internal com bustion

 engines.AUSTRALIA & OCEANIA/182.9 1.7% of world total

AFRICA / 344.4 3.1% of world total

SOUTH & CENTRAL AMERICA / 552.9 5.0% of world total

NORTH AMERICA / 2838.6 25.6% of world total

EUROPE/2840.8 25.6% of world total

ASIA/4339.8

39.0% of world total