Physics Flashcards
RP 2:
What is the aim of this practical?
RP 2:
To investigate the effectiveness of different materials as thermal insulators
RP 2:
What equipment does this practical require?
RP 2:
- Smaller beaker (250cm^3)
- Larger beaker (500cm^3)
- Kettle
- Water
- Thermometer
- Rubber bands
- Stopwatch
- Insulating materials
- Cardboard
- Heatproof mat
RP 2:
What is the independent variable in this practical?
RP 2:
Time, t (s)
RP 2:
What is the dependent variable of this practical?
RP 2:
Temperature, T (°C)
RP 2:
What variables should be controlled in this practical?
RP 2:
- Volume of water
- The temperature of the water at the start of the experiment
- The thickness of each material
RP 2:
Outline a method for a suitable experiment to investigate the effectiveness of different insulators:
RP 2:
1) Set up the apparatus by placing a small beaker inside the larger beaker
2) Fill the small beaker with 80 cm^3 boiling water from the kettle
3) Place a piece of cardboard over the beakers as a lid. It should have a hole suitable for a thermometer and place the thermometer through this hole and into the water in the small beaker
4) Record the temperature of the water in the small beaker and start the stopwatch
5) Record the temperature of the water every 2 minutes for 20 minutes, or until the water reaches room temperature
6) Repeat the experiment, each time changing the cardboard for another insulating material (in any order) and also without any insulation at all
RP 2:
What’s the First Step in investigating the effectiveness of thermal insulators?
RP 2:
1)Set up the apparatus by placing a small beaker inside the larger beaker
RP 2:
What’s the Second Step in investigating the effectiveness of thermal insulators?
RP 2:
2)Fill the small beaker with 80 cm^3 boiling water from the kettle
RP 2:
What’s the Third Step in investigating the effectiveness of thermal insulators?
RP 2:
3)Place a piece of cardboard over the beakers as a lid. It should have a hole suitable for a thermometer and place the thermometer through this hole and into the water in the small beaker
RP 2:
What’s the Fourth Step in investigating the effectiveness of thermal insulators?
RP 2:
4)Record the temperature of the water in the small beaker and start the stopwatch
RP 2:
What’s the Fifth Step in investigating the effectiveness of thermal insulators?
RP 2:
5)Record the temperature of the water every 2 minutes for 20 minutes, or until the water reaches room temperature
RP 2:
What’s the Sixth Step in investigating the effectiveness of thermal insulators?
RP 2:
6)Repeat the experiment, each time changing the cardboard for another insulating material (in any order) and also without any insulation at all
RP 2:
How would the results for this experiment be presented?
RP 2:
Plot a graph of temperature against time and draw a curve of best fit
- Plot all the curves for each material on the same axis
RP 2:
What information does the graph display about the rate of energy transfer?
RP 2:
The graphs should show that the temperature falls quickly at high temperature, then more slowly.
This is because:
When water is at a high temperature: there is a greater temperature difference between it and room temperature which creates a high rate of energy transfer
When water is at a low temperature: there is less temperature difference between it and room temperature. This creates a low rate of energy transfer
RP 2 :
Safety Precautions:
RP 2:
- Keep water away from all electrical equipment
- Make sure not to touch the hot water directly
- Run any burns immediately under cold running water for at least 5 minutes
- Do not overfill the kettle
- Place the small beaker inside the large beaker first before pouring water in, since the small beaker will become very hot
- Make sure all the equipment is in the middle of the desk, and not at the end to avoid knocking over the beakers
- Carry out the experiment only whilst standing, in order to react quickly to any spills