Energy 11.1 Aiming for 8

Required practical 2: Testing sheets of material as insulators

Specification reference:

  • P.1.2.1 Energy transfers in a system
  • MS 1a, 2a, 2c, 4c
  • WS 1.2, 2.1, 2.2, 2.3, 2.4, 2.6, 2.7, 3.1, 3.2, 3.3, 3.5, 3.6, 3.7, 3.8, 4.1

Aims

You are going to plan and carry out a two-part investigation into the effectiveness of thermal insulators.

You will make predictions based on a hypothesis about how heat conducts through an insulator, and present your results. You will evaluate your investigation, thinking about sources of error, reproducibility, and the validity of your conclusions.

Learning outcomes

After completing this practical, you should be able to:

  • plan and carry out an investigation into a factor affecting the effectiveness of a thermal insulator
  • accurately measure temperatures to compare the effectiveness of thermal insulators
  • evaluate the validity of conclusions drawn from results
  • suggest explanations for the different thermal conductivities of materials.

Equipment and materials

  • eye protection
  • four identical containers (beakers, boiling tubes, or metal cans)
  • measuring cylinder
  • four thermometers
  • stopwatch
  • four materials to test as insulators
  • elastic bands or tape
  • aluminium foil or cling film (if needed for lids)
  • access to hot water
  • graph paper

Method

Part 1: Comparing different insulators

Plan an experiment to investigate the effectiveness of different types of insulator.

The safety precautions and an equipment list have already been written for you.

In your plan you should include:

  • a list of the independent, dependent, and control variables
  • a clear step by step method.

Part 2: Comparing different thicknesses of an insulator

Select one type of insulator (or your teacher may tell you which one to use), and plan an experiment to investigate the effectiveness of different numbers of layers of this material when used as an insulator.

In your plan you should include:

  • a list of the independent, dependent, and control variables
  • a clear step by step method
  • a hypothesis about how heat conducts through an insulating material
  • a prediction, based on your hypothesis, for your experiment.

Results

For each part of the investigation, create a suitable table to record your results.

Questions

Part 1

1Draw a graph to show your results.(5 marks)

2a State which material had the lowest thermal conductivity, and suggest an explanation.(2 marks)

bState which material had the highest thermal conductivity, and suggest an explanation.(2 marks)

3Comment on the reproducibility of your results.(2 marks)

4a Describe a source of error in the experiment.(1 mark)

bSuggest a way to improve the experiment by reducing or eliminating this error. (1 mark)

5Comment on how valid your conclusions are for this experiment.

Hint: your conclusions are valid if your experiment measured what it aimed to measure, with no variables changing apart from your independent and dependent variables. (2 marks)

Part 2

1Suggest why a graph of the results should be a bar graph rather than a line graph. (1 mark)

2Draw a graph to show your results.(5 marks)

3Describe what your results show, and comment on whether they agree with your prediction.(2 marks)

4Suggest an explanation for your findings.(4 marks)

© Oxford University Press 2016

This resource sheet may have been changed from the original.1