Breaking Investigation

Finally we attached the air brake to a clamp for support and placed it on a table and made sure the air brake was directly 2 meters above the ground.

To make the experiment fair we will always keep the air brake at the same level because if the air brake is at different heights during the experiment, the force of gravity could upset our results by giving us an anomalous result. To make it a fair experiment we will also keep the area of the 8 cardboard blades the same so that when the blades push up against gravity, each trial will be fair. Also to make it a fair experiment we will take 3 trials for each mass category and then work out an average. This should help repair any anomalous results taken.

PREDICTION

I think the key factors that could effect my experiment could be the area of the cardboard blades and the force of gravity.

I predict that "as more mass is added, the air brake will become less effective". This will happen because as the mass pulls on the air brake and the gravity pushes down, the air brake will slowly become less effective which will lead to trials becoming faster as mass is added.

MY RESULTS

My results in a graph....

mass

Time taken in first trial (s)

Time taken in second trial (s)

Time taken in third trial (s)

Average time for 3 trials (s)

20g

23.37

20.49

20.34

21.41

30g

5.61

4.83

5.32

5.25

40g

4.17

4.13

4.22

4.17

50g

3.07

2.94

3.38

3.13

60g

4.01

2.91

4.58

4.23

70g

2.15

0.96

1.92

1.94

80g

2.28

1.87

1.92

2.02

90g

0.49

0.84

1.33

0.89

My results in a line graph....

CONCLUSION

My results clearly back my prediction that "as more mass is added, the air brake will become less effective". If you ignore a few anomalous results, you can clearly see that my graphs back and show that the theory is right!

EVALUATION

Although my results were not particularly of high standard, they backed the theory and were quite reliable. My results could have been a bit better if I could have avoided those anomalous results, which upset the average a bit. It was good that we took 3 time trials instead of 1, which helped us to get a bit of a more accurate result. We could have taken 5 time trials instead of 3 if we wanted more accurate results (which we do).

We could of also made the string a bit longer so instead of timing it until the mass stopped in mid-air, we could of timed it until the mass hit the ground; This would help the time keeper to get a more accurate result.

I think that my decision to keep the cardboard blades the same on the trails and change the mass worked out very well.

If we would have changed the blades and kept the mass the same, I think we would have got pretty much the same set of the results. Although the theory for that experiment would have a different saying, something like "as you add more wings, the air brake becomes more effective", it really has the same meaning as our theory but written in a different way.

28/04/07, page 1/2

By Shaminder Singh Juttla