Which material is best for muffling sound?

1. Which material is best for muffling sound? Miss M Gheewala

2. Professor Big-Hair and Professor Bee-Hive have a problem. They can’t do any work, because their alarm clock is constantly ringing and the off switch is broken. Professor Big-hair thinks if they wrap it in a sheet, they can muffle the sound so they won’t be able to hear it. Professor Beehive thinks they should do an experiment with different materials, to see which one will muffle the sound best. She says they should wrap the alarm clock in each of the materials, and see if they can still hear it ringing.

3. Which material do you think will be good at muffling the sound? Fill in the gaps in these sentences about the experiment. Choose the right words from the boxes at the bottom. The professors should wrap the _______________ in each ___________ they are testing. They should make sure they use ________________ number of layers of each material, and they leave ______________ gaps when they wrap up the alarm clock. no material the same different alarm clock notebook a tiny bubble wrap

4. When you do an experiment, it’s important to make sure that it’s a fair test. Doing a ‘fair test’ means doing an experiment where you change only _______________. To test which material muffles sound best, you must only change the _______________ each time – you have to make sure you use the ______________ number of layers for each wrapping, that you’ve used the same __________________________ to muffle each time, and you measure how ______________ it is in the same way each time. If you changed the material and changed the number of layers as well, you __________ know if the result was because of the material or the number of layer. Sound Would Same two things weather material different your socks One thing Wouldn’t loud hear always

5. Which materials are we going to use? Materials we are going to use in this investigation are: • Newspaper • Bubble wrap • Fabric • Cardboard boxes • Coats Which material do you predict to be the best at muffling sound?

6. Method What are you going to do? How are you going to do it? What will you need to keep the same or change?

7. Results In your groups use the following table to investigate if your material is the best at muffling sound.

8. Class results

9. Conclusion Which material was best at muffling sound? Remember the quieter it made the sound, the better it was at muffling sound. How can you compare the different materials?

10. Can you write a letter to Professor Big-Hair and Professor Beehive to explain your findings from your investigation. Explain in your letter what you did and how you reached the final solution. Ensure you give the Professors advice on fair testing and why this is important.