Physics: Module 3

• Solids are generally better conductors than liquids and gases since in solids the particles are arranged close together and therefore heat energy can be/is transferred through conduction when the particles gain heat energy and vibrate faster, colliding with their neighbor and transferring the heat/thermal energy to them.
• These 'neighboring' particles/molecules would have now gained kinetic energy as compared to liquids where the particles are further apart than in solids and even further apart in gases.
• ��/𝑡= −𝑘𝐴 ∆𝜃/∆𝑥
• SI Unit for thermal conductivity: Watts per meter Kelvin (W/m·K)
• Density is defined as the mass per unit volume of a substance. SI Unit is kg/m3.
• Pressure is defined as the force per unit area exerted on a surface. SI unit is N/m2.
• Temperature values on the Empirical Scale:

  �� = 𝑋𝜃− 𝑋0 / 𝑋100 × 𝑋0 x 100
• Explanation of the reason why different thermometers when using the Empirical centigrade scale do not agree: the difference in reading is because different thermometric properties respond differently and uniquely to the change in temperature between the fixed points.
• Heat Capacity, C is defined as the amount of heat energy required to increase the temperature of a substance by 1 degree.
• Specific Heat Capacity, c is defined as the amount of heat energy required to increase the temperature of 1kg of a substance by 1 degree.
• Specific Heat Capacity, c: E = mcΔθ
• Latent Heat: Eh = mL
• Specific Latent Heat is the energy required to change the state of a substance.
• Melting is the process whereby a solid changes into a liquid without a temperature change (fusion).
• Boiling is the process whereby a liquid changes into a gas without a temperature change (vapourization).
• Thermal Conduction is defined as the process by which thermal energy flows from a region of higher temperature to a region of lower temperature without any net movement of the material itself.
• Thermal Radiation is defined as the transfer of heat by electromagnetic waves.
• Thermal Convection is defined as the transfer of thermal energy in fluids (liquids and gases) due to the bulk movement of the fluid as a result of a density change.
• Molar Heat Capacity: The amount of energy needed to raise the temperature of 1 mole of a substance by 1 degree Celsius.
• Stress is defined as the force, F, per unit area, A of the material.