Topics to revise
Evolution P2
Energy P1
Required practical - Specific heat capacity
Required practical - Insulation
Almost there, keep it going. If you have followed our program, you have time left once study leave starts to revisit areas you find hard.
Specific heat capacity
Investigate the specific heat capacity of one or more materials by linking the energy supplied to the rise in temperature.
Check your understanding with these quick common questions. Use the drop down boxes to see the correct answers.
Specific heat capacity
Different materials heat more or less easily. Water is very hard to heat, metals heat easily. This investigation expects you to calculate the specific heat capacity, by first finding the mass, temperature change and energy delivered to different types of metal.
Independent variable: Material being heated, usually different metals
Dependent variable: Temperature change of the material. - This is then used to calculate the specific heat capacity.
Control variables (3): Mass of the block; initial temperature; heater voltage/current (power).
Joulemeter to measure energy (easiest answer on foundation)
Ammeter, voltmeter and stop watch to calculate Energy (higher)
Thermometer
Metal blocks
Heater
Accuracy can be improved by: digital thermometers; reading thermometer at eye level.
Validity can be improved by: Keeping starting temperature, the same; ensuring no heat loss by using an insulating layer.
Metals will have a lower specific heat capacity than non metals as they have free electrons. Look out for how this information might be applied in a question, e.g. a lower specific heat capacity will take less energy to heat up.
For all physics practicals - try to start with an equation (use the equation sheet)
Change in thermal energy = change in temperature x mass x SHC
Find the mass with a balance
Find the temperature change by using the thermometer to take the temperature at the start and after 5 minutes/end.
Find the energy by using a joulemeter (Foundation) -
Or putting the voltmeter in parallel, the ammeter is series and using the stopwatch to record time.
Calculate energy = V*I*T = Voltage (potential difference) x Current x Time
Rearrange the specific heat capacity formula to get
SHC = Energy/ Mass x Temperature change
Thermal Insulation
Investigate how different materials and thicknesses affect thermal insulation and cooling rates.
Check your understanding with these quick common questions. Use the drop down boxes to see the correct answers.
Thermal insulation
Insulation reduces heat loss. Thermal conductivity is a phrase used to describe how well heat moves through a material. Good insulations have very high thermal conductivity.
Independent variable: Type or thickness of insulator
Dependent variable: Rate of cooling (°C per minute)
Control variables: Same beaker type, same starting temperature, same volume of water
Thermometer
Ketal for hot water
Lid
Accuracy can be improved by: Using lids and digital thermometers to reduce heat loss and reading errors.
Validity can be improved by: Keeping starting temperature, volume, and beaker type the same.
Describe: More/Better insulation or greater thickness → slower cooling.
Explain: Insulators reduce energy transfer by conduction, convection or radiation, so the water loses heat more slowly. Insulators have lower thermal conductivity.
A formula is not needed for this practical
Pour equal volumes of hot water into identical beakers.
Wrap each beaker with a different insulating material (or vary thickness).
Cover each with a card lid and place a thermometer in the water.
Record the starting temperature and then every minute for 10 minutes.
Plot temperature vs time for each insulator.
Repeat 3 times for each temperature and calculate a mean