# Speed of sound practical

1. May 30, 2013

### Knightycloud

1. The problem statement, all variables and given/known data
In the practical for calculating speed of sound using the resonance tube why do we put wool to the bottom of the cylinder?

2. Relevant equations
-

3. The attempt at a solution
To prevent the tube from hitting the bottom hard for it can be broken.

2. May 30, 2013

### Simon Bridge

3. May 30, 2013

### Knightycloud

Yes, that's the practical I'm referring to. We normally put wool to the bottom and fill it with water. Why do we put wool like that? Is it to prevent the tube hitting the cylinder causing the glass to break?

4. May 30, 2013

### Simon Bridge

In that experiment I see a tube but I don't see a cylinder.

The way to tackle a question like that is to make a list of all the things the cotton wool could be for and eliminate the unlikely uses.

Certainly the resonance tubes are easily broken in the course of this experiment - what with it being about resonance and all - so, if the tube has to rest on a solid surface, it should have some padding to sit on or risk shattering.

Last edited: May 30, 2013
5. May 30, 2013

### Knightycloud

Yep, It's for the safety I think. Thanks for the help and the tip! :)

6. May 30, 2013

### Simon Bridge

In general - it is best practice not to assume that people on the other side of the world living in different cultures and experiencing different education systems are familiar with the specific apparatus and setup being used in your classroom. Try to describe everything that is pertinent to your question and you are more likely to get a useful answer quickly.

It's also great practice for writing reports/papers that get A's.
;)

7. May 31, 2013

### Knightycloud

Haha, Yea I understand about that system thingy! and of course hard work earns A's :D

Well it's like this. You first fill the cylinder with water and put wool into it and drown it to the bottom using a rod or something. Then get the tube into the cylinder and sound the tuning fork and lift the tube until you hear a sharp sound. measure the length, put it into the equations, that's all. They say. No mention about the job done by wool.