An experiment to see how a balloon falls.

Drag=6πηrv

Apparatus.

I will need:

• 4 meter tape measure,
• A balloon,
• 25 paper clips,
• A stopwatch.

Diagram of Apparatus.

Prediction

I predict that the relationship between time to hit ground and weight will be a straight forward straight line relationship until it reaches terminal velocity. The balloon will slowly become less steep. The reason that I think this will be the relationship is that the heavier balloons will not reach terminal velocity because they will hit the ground to soon.

I think that the graph will look like this. However please note that even for a lead shot with no drag it can never reach the ground in zero seconds

Method.

I think that the best way to determine how a balloon falls is to see how it falls with various weights on it.

• I will hopefully drop the balloon from a height of four meters however I might be forced by lack of space to drop it from three and this should be ok.
• I will weigh the balloon by placing paper clips on the tail of the balloon.
• It is very important that I start the clock exactly when I release the balloon this should not be to hard however stopping the clock when the balloon reaches the bottom will be the hard part.

Results.

I have underlined the results I regard as anomalous. There are a variety of possible reasons for the anomalies such as a gust of wind or stopping the clock to late. I have also taken them out of the calculation to determine the average.

Analysis

I think that as my plan was relatively easy to carry it out in the time allotted, it saved me from having to hurry the last few results and get dubious results I think this is reflected in my data as there are only two anomalies. The result curve is a lot less steep than I expected however it does remain similar to my original prediction. I thought originally that some of the heavier balloons would not reach terminal velocity and still be accelerating when they hit the ground however it seems that the balloons where all heavy enough to reach terminal velocity very quickly. I would have discovered this in my preliminary work but I never got to test this method out before I actually did it because in my preliminary work I discovered that my previous method was fundamentally flawed.

Evaluation.

Bar the two anomalies I think that my result were acceptably consistent baring in mind such uncontrollable variables as wind gust because someone opened a door. I could have made the results more reliable by doing them in some form of extra large tube with a stagnant atmosphere this would have removed such variables as the wind. I could have tried doing the experiment with a balloon filled with Helium and dropped from a lower height in order to discover the exact weight need for a balloon to reach terminal velocity before hitting the ground when drooped from maybe 1 meter.