Week 16 20th April

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)

1. Change in thermal energy = change in temperature x mass x SHC

2. Find the mass with a balance

3. Find the temperature change by using the thermometer to take the temperature at the start and after 5 minutes/end.

4. Find the energy by using a joulemeter (Foundation) - 

5. Or putting the voltmeter in parallel, the ammeter is series and using the stopwatch to record time. 

6. Calculate energy = V*I*T = Voltage (potential difference) x Current x Time

7. Rearrange the specific heat capacity formula to get

8. SHC = Energy/ Mass x Temperature change