Conduction

Conduction

Conduction Heat conduction (as opposed to electrical conduction) is the flow of internal energy from a region of higher temperature to one of lower temperature by the interaction of the adjacent particles (atoms, molecules, ions, electrons, etc.) in the intervening space. Note: it’s the rate (Φ) at which heat is transferred, not the amount (Q) of heat transferred. Φ̅ = ΔQ Δt Φ = dQ dt ...

Read More »

The Nature Of Waves

The Nature Of Waves

The Nature Of Waves The Nature Of Waves examples, examples, examples.The Nature Of Waves basic properties types 1 classed by medium mechanical electromagnetic gravitational matter waves types 2 classed by orientation of change transverse synonyms shear examples: light and all electromagnetic waves musical instruments chordophones – vibrating strings (violin, guitar, piano) membranophones – vibrating membranes (drums, vocal chords, kazoo?) idiophones ...

Read More »

Chemical Potential Energy

Chemical Potential Energy

Chemical Potential Energy Calorimetry and so on. Q = mcΔT Chemical Potential Energy; Burn a sample of the substance in oxygen, use the heat given off to warm a bit of water and watch the temperature rise. When comparing substances, it’s often more instructive to speak of their specific energy or specific work or gravimetric energy density or volumetric energy density (energy ...

Read More »

Latent Heat

latent heat formula

Latent Heat discussion Name the 6 major phase changes (including synonyms). Latent Heat absorbed or released as the result of a phase change is called latent heat. There is no temperature change during a phase change, thus there is no change in the kinetic energy of the particles in the material. The energy released comes from the potential energy stored ...

Read More »

Sensible Heat

Sensible Heat

Sensible Heat introduction Sensible Heat: Heat that results in a temperature change is said to be “sensible” (although this term is falling out of favor). This is because it can be “sensed” I assume. 1781 Wilcke comes up with the concept of specific heats. 1819 Objects have a heat capacity, while materials have a specific heat capacity (often just called specific heat) was first ...

Read More »

Phases

phases

Phases the basics Phases: This section has become a disaster of epic proportions. gas & chaos have related etymology Jan van Helmont (1577–1644) Belgium Notes from some long forgotten source. “Chaos (χαος) was used to define the most disperse and fluid state of matter, that in which no particular order could be observed. Interestingly enough, when van Helmont wanted to refer to ...

Read More »

Kinetic-Molecular Theory

Kinetic-Molecular Theory

Kinetic-Molecular Theory postulates Kinetic-Molecular Theory: The postulates of kinetic–molecular theory (also known as molecular–kinetic theory) start very sensibly with… Molecules …and… Moving Which can be expanded to… Matter be molecules …and… Molecules be moving Then we need another postulate to explain what molecules are… Molecules be small …and how they behave… Molecules be elastic If you think it sounds like ...

Read More »

Gas Laws

Gas Laws

Gas Laws introduction Gas Laws: The gas laws are a set of intuitively obvious statements to most everyone in the Western world today. It’s hard to believe that there was ever a time when they weren’t understood. And yet someone had to notice these relationships and write them down. For this reason, many students are taught the three most important ...

Read More »

The Atomic Nature Of Matter

The Atomic Nature Of Matter

The Atomic Nature Of Matter atoms do exist The Atomic Nature Of Matter : What belongs in this section? Just chemistry? Or chemistry and physics? chemistry democritus philosophy, not science everything has to have an ultimate thing? chemical elements Earth, Water, Air, Fire, quintessence (aether) yellow bile (fire), black bile (earth), blood (air), and phlegm (water) Fire, Earth, Metal, Water, ...

Read More »

Thermal Expansion

thermal expansion examples

Thermal Expansion Solids Thermal Expansion: For many solids, expansion is directly proportional to temperature change. Δℓ = αℓ0ΔT Areas expand twice as much as lengths do. ΔA = 2αA0ΔT Volumes expand three times as much as lengths do. ΔV = 3αV0ΔT applications buckling expansion gap/joint anti-scalding valve bimetallic strip, thermostat expansion of holes (mounting train tires) “What’s more, the aircraft expands by 15-25 centimeters during flight ...

Read More »