thermal physics

• What is the specific latent heat of fusion?

  The energy needed to change the state of unit mass from solid to liquid without a change in temperature
• What is the specific latent heat of vaporization?

  The energy needed to change the state of unit mass from liquid to vapor without a change in temperature
• What is the equation for latent heat?

  Q = m x L
• What is the ideal gas law equation?

  The ideal gas law is represented by pV = nRT
• What does Ek = (3/2)kT represent?

  It represents the kinetic energy of a molecule
• What is the root mean square speed of gas molecules?

  It is the measure of the average speed of gas molecules in a container
• What is the molar mass of one mole of O2?

  0.032 kg
• What is the significance of elastic collisions in gas molecules?

  Elastic collisions mean that kinetic energy is conserved during collisions between gas molecules
• What is Boltzmann's constant?

  It is a physical constant that relates the average kinetic energy of particles in a gas with the temperature of the gas
• What are the key assumptions of the ideal gas model?

  • Gas molecules are in constant random motion
  • Collisions between molecules are elastic
  • There are no intermolecular forces
  • The volume of gas molecules is negligible compared to the volume of the container
• What are the implications of the ideal gas law in thermal physics?

  • Describes the behavior of ideal gases
  • Relates pressure, volume, temperature, and number of moles
  • Useful for calculations in thermodynamics
• How do you calculate the total internal energy of a gas?

  • Use the equation E = 3/2 nRT
  • Where n is the number of moles, R is the gas constant, and T is the temperature in Kelvin
• What is the relationship between temperature and kinetic energy in gases?

  • Higher temperature results in higher average kinetic energy of gas molecules
  • Kinetic energy is directly proportional to temperature
• What is the formula for calculating work done in gas expansion?


  • Work done W = pV
  • Where p is pressure and dV is the change in volume
• Internal energy - sum of the random distribution of the kinetic and potential energies if its molecules
• Work can be done or energy can be transferred to increase an objects internal energy
• 1st law of thermodynamics: the change in internal energy of an object is equal to the total transfer of energy due to work done and heating
• Absolute zero - the temperature at which all molecules have no kinetic energy and no thermal energy
• specific heat capacity - the amount of energy needed to raise the temperature of 1kg of a substance by 1 kelvon without a change of state
• Q = Mc (change in)0
• Specific latent heat of fusion - the amount of energy required to change the state of one kilogram of a substance from liquid to solid, or vice versa, without any change in temperature.
• A substance with low specific heat capacity heats and cools quickly
• Substance with high specific heat capacity heats and cools slowly
• Specific latent heat of vaporization - energy needed to change the state of 1kg of substance from liquid to vapour without a change in temperature
• p1 v1 = p2 v2
• v1 / t1 = v2 / t2
• p1 / t1 = p2 / t2
• Boyles Law: pv is constant, temperature is fixed.
• In boyles law pressure is inversely proportional to volume
• Charle's Law: V/T is constant, pressure is fixed.
• In charles law volume is directly proportional to temperature
• Pressure law: p/t is constant, volume is fixed
• in the pressure law pressure is directly proportional to temperature
• The ideal gas equation is PV=nRT
• P is pressure (Nm^-2)
• pv = NkT
• How to calculate root mean square speed (crms)


  Add squares of each speed and divide by number of molecules
• Why is no in temperature when latent heat is added


  All te energy goes into weakening the bonds between molecules, so no gain in kinetic energy or temperature
• Charles law helps to calculate absolute zero
• Charles law helps to calculate absolute zero