## Discussion

#### Key Findings

• From the data we collected, we can to conclude that the surface area affects the speed at which the wind turbine turns. The greater the surface area of the blades, the faster the speed of the wind turbine which helps create more voltage.
• From the data collected we also got to know that shape indeed matters when it comes it the blade size. The broader the blade size, the more voltage produced.

#### Explanation of Key findings

• The greater the surface area of the blades, the faster the speed of the wind turbine which helps create more electricity can be seen through the amount of voltage produced by the  respective blades. Since the blades differ in surface area, the result (which is the amount of voltage produced) changes accordingly.  If we were to compare Template A and B, A has greater surface area whereas B has lesser. Hence the A produced 0.008 volts whereas B produced 0.005 volts.

Figure 1 shows the various kinds of blades.
Figure 2 shows our data.
• The broader the blade, the more electricity it helps to generate. This can be seen through Template A and B, when they are compared. As an average reading Template A was noted as 0.008 volts and Template B was noted as 0.005 volts. It also coincides with our hypothesis which is the broader and longer the blade, the more electricity is generated.

#### Hypothesis

Our hypothesis is : The broader and longer the shape of the blade, the greater amount of voltage produced.

#### Further Evaluation of Hypothesis:

As this was a hypothesis driven research we had always had to keep our hypothesis in mind. Our hypothesis was also proven to be correct and this finding is supported by our experiment data.  This can be seen by when the blade shapes were broad, they tend to produce a higher voltage. But when the blade shapes thinner, they tend to produce a lesser voltage or not produce anything at all, take Template E for an example.

From this we can conclude and prove that our hypothesis is correct. Our hypothesis is : the broader and longer the shape of the blades are, the greater amount of electricity produced by the wind turbine.

#### Areas for improvement:

There are several things which can be improved on. All experiments can be improved on!

Firstly, when we cut the blades out from the wood, a significant amount of wood which is not suppose to be cut is also cut off. Though the inaccuracies may be minor, but they do have an impact on the data we collect, since all the blades after cutting out has different sets of measurements, the data would not be as accurate. To prevent this we can always measure the measurements more, for example: the length is 8cm, we can always mark up till 8.5cm so as to get a 8cm when we cut out with a plus and minus.

Secondly, when we cut out the blades and if we let everyone in the group cut it out, everybody will cut differently (their way of cutting is different), thus again a significant amount of wood which is not suppose to be cut off would be cut off. Though this is something very minor, but again the results would not be as accurate. We suggest division of labour, hence appoint one person to cut out the blades so the difference will be as minimal as possible.

Thirdly, when we want to test out our blades, then we should mark a distance from the wind source to the wind turbine. This plays a very important role as it affects fairness of the experiment. If one blade set is 20cm away from the wind source and the other is 30cm away, then of course the one which is 20cm away will produce a higher voltage. We suggest that marking a common distance will be effective and efficient as all would start from the same starting point.

Fourthly, when we should mark the cork consistently with the same angles on all the corks. This plays a very important role as the distance at which the blades are spread out should be equal as they affect the way the turbine spins. To prevent the shaky turbine, we should take a 360 degree protector and mark out 50 degree and then poke the blades in to ensure the equal distance.