Thermodynamics - PDF document

Thermodynamics � ✁ ✂ ✄ ☎ ✆ ✂ ✝ ✝ ✞ ✟ ✠ ✝ ✂ ☎ ✝ ✡ ✠ ✝ ☛ ✟ ☞ ✌ ✍ ✎ ☛ ☎ ✏ ✑ ✡ ✑ ✟ ✂ ✝ ✎ ✒ ✟ ✠ ☞ ✓ ✄ ✔ ✝ ✂ ✕ ✂ ☛ ✎ ✗ ✠ ✄ ✁ ✓ ✠ ✍ ✑ ✏ ✗ ✑ ✌ ✝ ☛ ✘ ✏ ✎ ✒ ✔ ✏ ✟ ✠ ✝ ✎ ✝ ✂ ✒ ✍ ✟ ✂ ☛ ✎ ✑ ✁ ✄ ✂ ☎ ☛ ✟ ✏ ✄ ✎ ✑ ✖ ✁ ✂ ✄ ☎ ☛ ✎ ✌ ✏ ✎ ✟ ✄ ✟ ✠ ✝ ✂ ☎ ☛ ✘ ✝ ✎ ✝ ✂ ✒ ✍ ✞ ✝ ✍ ✔ ✄ ✂ ✌ ✑ ✁ ✄ ✂ ✟ ✠ ✝ ✂ ☎ ✄ ✌ ✍ ✎ ☛ ☎ ✏ ✗ ✑ ✙ ✟ ✝ ☎ ✓ ✝ ✂ ☛ ✟ ✚ ✂ ✝ ☞ ✠ ✝ ☛ ✟ ☞ ✏ ✎ ✟ ✝ ✂ ✎ ☛ ✘ ✛ ✟ ✠ ✝ ✂ ☎ ☛ ✘ ✝ ✎ ✝ ✂ ✒ ✍ ☞ ✝ ✎ ✟ ✂ ✄ ✓ ✍ Some History • ✜ ✢ ✣ ✤ ✥ ✦ ✧ ★ ✩ ✪ ✫ ✬ ✭ ✦ ✥ ✮ ✯ ✧ ✰ ✥ ✱ ✬ ✭ ✦ ✥ ✮ ✯ ✧ ✰ ✥ ✯ ✲ ✳ ✦ ✴ ★ ✦ ✪ ✧ ✯ ✲ ✵ ✦ ✧ ✦ ✪ ✶ ✰ ✦ ✱ ✷ ✸ ✱ ✫ ✱ ★ ✦ ✭ ✱ ✹ ✶ ✷ ✺ ✦ ✪ ✧ ✦ ✻ ✼ ✫ ✽ ✦ ✾ ★ ✷ ✧ ✿ ✱ ✲ ✯ ✾ ✱ ❀ ✭ ✷ ★ ✰ ✺ ✯ ★ ✦ ✻ ✼ ✫ ✭ ✷ ★ ✰ ✷ ✧ ✷ ✸ ✥ ✦ ✲ ✦ ✱ ★ ✰ ✯ ✲ ✷ ✼ ❁ ✦ ✥ ★ ✱ ✳ ❂ ✲ ✯ ✧ ✦ ★ ✱ ✯ ✪ ✷ ✩ ✧ ✻ ★ ✮ ✦ ✱ ✩ ✧ ✵ • ✜ ❃ ✣ ✤ ✯ ✧ ✻ ✜ ❄ ✣ ✤ ✥ ✦ ✧ ★ ✩ ✪ ✰ ✦ ✱ ✬ ★ ✮ ✦ ✪ ✭ ✷ ✻ ✫ ✧ ✯ ✭ ✰ ✥ ✱ ✬ ✰ ✧ ★ ✦ ✪ ✧ ✯ ✲ ✦ ✧ ✦ ✪ ✶ ✫ ✷ ✸ ✱ ✫ ✱ ★ ✦ ✭ ✱ ✯ ✧ ✻ ✰ ★ ✱ ✪ ✦ ✲ ✯ ★ ✰ ✷ ✧ ★ ✷ ✾ ✷ ✪ ❅ ❀ ❆ ✧ ✻ ✩ ✱ ★ ✪ ✰ ✯ ✲ ✪ ✦ ✺ ✷ ✲ ✩ ★ ✰ ✷ ✧ ❇ ❈ ✲ ✦ ✥ ★ ✪ ✰ ✥ ✰ ★ ✫ ✯ ✧ ✻ ✭ ✯ ✶ ✧ ✦ ★ ✰ ✱ ✭ ✬ ✥ ✷ ✧ ✥ ✦ ❂ ★ ✱ ✷ ✸ ✥ ✮ ✯ ✪ ✶ ✦ ✹ ✸ ✰ ✦ ✲ ✻ ✹ ✪ ✯ ✻ ✰ ✯ ★ ✰ ✷ ✧ ❇ • ❉ ❊ ✣ ✤ ✥ ✦ ✧ ★ ✩ ✪ ✫ ✬ ✪ ✦ ✲ ✯ ★ ✰ ✺ ✰ ★ ✫ ✯ ✧ ✻ ❋ ✩ ✯ ✧ ★ ✩ ✭ ✭ ✦ ✥ ✮ ✯ ✧ ✰ ✥ ✱ ❀ ★ ✮ ✦ ✲ ✯ ✾ ✱ ✷ ✸ ★ ✮ ✦ ✯ ★ ✷ ✭ ✰ ✥ ✾ ✷ ✪ ✲ ✻

� ✁ ✂ ✄ ☎ ✆ ✝ ✞ ✁ ✟ ✠ ✡ ☛ ✄ ☞ ✁ ✌ ✍ ✎ ✆ ☞ ✏ ✑ ✞ ✒ ✡ ☛ ✆ ✠ ✠ ✄ ✆ ✎ ✞ ✟ ☛ ✄ ✓ ✠ ✡ ☛ ✄ ☞ ✆ ☎ ☛ ✔ ✂ ✏ ☎ ✏ ✕ ✄ ✏ ✂ ☞ • ☛ ✎ ☛ ✄ ✖ ✍ ✑ ✁ ✎ ✞ ☛ ✄ ✗ ✆ ✠ ✏ ✁ ✎ • ✎ ✁ ✠ ✆ ☎ ☎ ✠ ✡ ☛ ✄ ☞ ✆ ☎ ☛ ✎ ☛ ✄ ✖ ✍ ✏ ✞ ✂ ✞ ☛ ✟ ✂ ☎ ✘ • ✄ ☛ ✗ ☛ ✄ ✞ ✏ ✕ ✏ ☎ ✏ ✠ ✍ ✏ ☞ ✙ ✁ ✞ ✞ ✏ ✕ ✏ ☎ ✏ ✠ ✍ ✠ ✁ ✄ ☛ ✆ ✑ ✡ ✆ ✕ ✞ ✁ ☎ ✂ ✠ ☛ ✚ ☛ ✄ ✁ • ✠ ☛ ☞ ✙ ☛ ✄ ✆ ✠ ✂ ✄ ☛ ✛ ✜ ★ ★ ✮ ✰ ✱ ❂ ✷ ✰ ✧ ★ ✹ ✯ ✲ ✲ ★ ✮ ✰ ✱ ✱ ✷ ✩ ✧ ✻ ✱ ❂ ✪ ✦ ★ ★ ✫ ✯ ✼ ✱ ★ ✪ ✯ ✥ ★ ✹ ★ ✮ ✷ ✩ ✶ ✮ We know what work is, but… What is heat?

• Work: mechanical energy • Heat: thermal energy… � ✞ ✠ ✡ ✏ ✞ ✆ ✖ ✁ ✁ ✌ ✌ ☛ ✟ ✏ ✎ ✏ ✠ ✏ ✁ ✎ ✁ � ✌ ✁ ✎ ✂ ✠ ✠ ✡ ✏ ✎ ✄ ✝ ☛ ✂ ✗ ☛ ☎ ☛ ✆ ✄ ✎ ☛ ✌ ✝ ✡ ✆ ✠ ☎ ✡ ☛ ✆ ✠ ✆ ✏ ✞ ✝ ✞ ✁ ✄ ☎ ✝ ✁ ✄ ✄ ✆ ✓ ✝ ✁ ✄ ☎ ☛ ✎ ☛ ✄ ✖ ✍ ✆ ✟ ✁ ✄ ✠ ✡ ✆ ✠ ☞ ✆ ✠ ✠ ☛ ✄ ✝ But what is energy? But what is energy? But what is energy? But what is energy? “We have no knowledge of what energy is …it is an abstract thing…” (Richard Feynman) Definition 1: a scalar quantity that describes the amount of work that can be performed by a force Definition 2: Energy is a property or characteristic (or trait or aspect?) of matter that makes things happen, or, in the case of stored or potential energy, has the "potential" to make things happen . By "happen", we mean to make things move or change condition. Examples of changes in condition are changes in shape, volume, and chemical composition (results of a chemical reaction). There are also changes in pressure, temperature, and density which we call a "change of state" in thermodynamics. Phase changes, such as changing from solid to liquid, or liquid to vapor, or back the other way, are also good examples of condition changes. Something happened! Good, but what about radiation?

My definition of energy My definition of energy My definition of energy My definition of energy Definition 3: a scalar quantity conveniently defined so that it is conserved in all physical processes taking place in a closed system, and that obeys certain symmetry principles. Energy comes in many inter convertible forms: -internal (atomic motion in solids, liquids & gases) -electrical & magnetic -chemical - in molecular bonds (coal power) -kinetic (wind power) -potential – gravitational (hydropower) -radiant (solar power) -nuclear – in proton-neutron bonds (nuclear power) … ENERGY obeys conservation laws!!! What is work? Mechanical work: scalar quantity describing the amount of energy transferred by a force acting through a distance = W F . d Units: [W] = [F].[d] = N.m (Newton.meter) = J = Joule