Physics Fall Solids Crystal Structure Density Elasticity Tension and Compression Scaling

Physics Fall Classification of matter? – Elements, – compound, – mixture,... Three (actually 4) states of matter. – Solid- fix shape, fix volume – Liquid- shape container, fix volume – Gas- shape container, volume container The Essence of Matter

Physics Fall Crystal Structure Diamond (Carbon)

Physics Fall Crystal Structure water ice

Physics Fall Density Mass Density = Mass/Volume Weight Density = Weight/Volume Units are Kg/m 3 Water density is 1000 Kg/m 3 or 1 g/cm 3

Physics Fall Elasticity F ~ -  x Hookes Law: Tension and Compression Tension Compression

Physics Fall Scaling

Physics Fall Scaling

Physics Fall Class Problems 1. Compared to a bar of pure gold, the density of a pure gold ring is A)slightly more. B) the same. C)less. D)much more. 2. If the volume of an object were to double while its mass stays the same, its density would A)halve. B)stay the same. C) double. D) become four times as great. 3. Stone slabs are stronger under A)tension. B)compression. C)same strength.

Physics Fall Class Problems 4. A metal block has a mass of 5 grams and a volume of 1 cubic centimeter. A piece of the same kind of metal with a volume of 2 cubic centimeters has a density of A)2.5 g/cc. B)5 g/cc. C)10 g/cc. 5. Eight little spheres of mercury coalesce to form a single sphere. Compared to the combined surface areas of the eight little spheres, the surface area of the big sphere is A)less. B)greater. C)the same.

Physics Fall Class Problems 6. An elephant eats less for its size than smaller animals because A) its radiating area is small compared to its volume. B) its ears are bigger. C) its radiating area is large compared to its volume. D) it is taller than other animals. E) it weighs more than smaller animals.