ARCHIMEDES

MATHEMATICIANINVENTOR of MACHINESDEFENDER of SYRACUSE andA COOL OLD MAN

ARCHIMEDES• Archimedes. once

said, "Give me a place to stand and rest my lever on, and I can move the Earth."

• He also invented the compound pulley and Archimedes'screw.

ARCHIMEDES• Archimedes was a

brilliant mathematician who helped develop the science of geometry.

• He discovered the relation between the surface area and volume of a sphere and those of its circumscribing cylinder and other geometrical formulas.

ARCHIMEDES PRINCIPLE• Archimedes discovered the principle

of displacement while stepping into a full bath. He realized that the water that ran over equaled in volume the submerged part of his body. Through further experiments, he deduced the principle of buoyancy, which is called Archimedes' principle.

• According to this principle a body immersed in a fluid loses as much in weight as the weight of an equal volume of the fluid

ARCHIMEDES PRINCIPLE

ARCHIMEDES PRINCIPLE• An object is subject to an upward force when it is immersed

in liquid. The force is equal to the weight of the liquid displaced. The apparent weight of a block of aluminum

• (1) immersed in water is reduced by an amount equal to the weight of water displaced. If a block of wood

• (2) is completely immersed in water, the upward force is greater than the weight of the wood. (Wood is less dense than water, so the weight of the block of wood is less than that of the same volume of water.)

• So the block rises and partly emerges to displace less water until the upward force exactly equals the weight of the block.

ARCHIMEDES• Archimedes uncovered a fraud

against King Hieron II of Syracuse using his principle of buoyancy. The king suspected that a solid gold crown he ordered was partly made of silver. Archimedes first took two equal weights of gold and silver and compared their weights when immersed in water. Next he compared the weights of the crown and a pure silver crown of identical dimensions when each was immersed in water. The difference between these two comparisons revealed that the crown was not solid gold.

ARCHIMEDES• Archimedes was born in Syracuse,

Sicily. He lived there most of his life. When the Romans attacked Syracuse, Archimedes invented weapons to defend the city.

ARCHIMEDES• Archimedes

invented a large solar mirror to set fire to Roman ships attacking Syracuse, Sicily.

ARCHIMEDES USED MACHINES TO DEFEND SYRACUSE FROM ROMAN

INVASION

ARCHIMEDES•After the capture of Syracuse during the

Second Punic War, Archimedes was killed by a Roman soldier who found him drawing a mathematical diagram in the sand.

•It is said that Archimedes was so absorbed in calculation that he offended the intruder merely by remarking, "Do not disturb my diagrams."