Thermal Physics: Objectives
Rosie
Heating matter
Must be able to Define and understand the meaning of specific heat capacity.
Activity
Measurement of specific heat capacities of solids and liquids: a direct method using an electric
heater will be expected.
Yvonne
Energy transfer
Calculation of energy transferred. Sources of serious experimental error should be identified and
understood.
Energy transfer = mcΔT
Activity
Joulemeter to measure electrical energy transfer using a temperature sensor and data logger.
Chris
Change of state
Must be able to Define and understand the meaning of Specific latent heat.
Understand that energy is needed to pull molecules apart.
Energy transfer = lΔm
Activity
Temperature sensor and data logger to display cooling curves — with and without changes of
state.
Alkis
Pressure
Solids transmit force, fluids transmit pressure.
Be able to Apply the equation p = F/A
Activity
You will not be given this equation
Pressure sensor to measure excess lung pressure.
Helen
The behaviour of gases
Experiment demonstrating that for a fixed mass of gas at constant V: p/T = constant
Activity
Use temperature and pressure sensors to investigate the relationship between the pressure and
temperature of a gas at a constant volume.
Josie
The absolute scale of temperature
Understand the concept of absolute zero of temperature.
Temp K = Temp oC + 273
Louisa
Ideal gas equation
Use a pressure sensor to demonstrate that, for a fixed mass of gas, at constant temp T:
pV = constant
For ideal gases pV = nRT
In calculations the amount of gas will be given in moles
You will not be given this equation
Dave
Be able to use and understand the ideal gas law.
Kinetic model of an ideal gas & Brownian motion
Be able to use of the model to explain the change of pressure with temperature.
Know the assumptions on which the model is founded.
p = 1/3 ρ <c2>
The average kinetic energy of molecules is proportional to the temperature (Kelvin).
Conservation of energy & Internal energy
Real gases have a random distribution of potential and kinetic energy amongst molecules.
Appreciation that hot and cold objects have different concentrations of internal energy.
Heating
Random interchange of energy between bodies in thermal contact, results in energy flowing from
hot to cold.
Electrical and mechanical working
Understand that forces can move either charges or masses. The process is ordered and
independent of temperature difference.
Andrew
The first law of thermodynamics
The increase in internal energy is equal to the sum of the energy given by heating and working.
Activity
Research the development of the laws of thermodynamics.
The heat engine
Understand the work done by an engine when energy flows from a hot source to a cold sink.
Activity
Demonstrate thermocouple engine.
Efficiency
Efficiency of energy transfer is useful output divided by input.
Maximum thermal efficiency = (T1– T2)
T1
Environmental considerations
Understand the use of energy and sustainable growth.
The heat pump
Calculate the work needed to pump energy from cold to hot.
Thermal Physics: Equations
The following equations will be provided to you.
You will find them at the back of your Unit 2 exam paper.