physics 1100 - fall 20111 solids crystal structure density elasticity tension and compression...
TRANSCRIPT
Physics 1100 - Fall 2011 1
Solids
• Crystal Structure• Density• Elasticity• Tension and Compression• Scaling
Physics 1100 - Fall 2011 2
• 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 1100 - Fall 2011 3
Crystal Structure
Diamond (Carbon)
Physics 1100 - Fall 2011 4
Crystal Structure
waterice
Physics 1100 - Fall 2011 5
Density
• Mass Density = Mass/Volume
• Weight Density = Weight/Volume
• Units are Kg/m3
• Water density is 1000 Kg/m3 or 1 g/cm3
Physics 1100 - Fall 2011 6
Elasticity
F ~ -xHookes Law:
Tension and Compression
Tension
Compression
Physics 1100 - Fall 2011 7
Scaling
Physics 1100 - Fall 2011 8
Scaling
Physics 1100 - Fall 2011 9
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 1100 - Fall 2011 10
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 1100 - Fall 2011 11
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.