Shape Of Carton-
If a carton is more streamline it has less air resistance and is not slowed down as much as a carton that has lots of air resistance.
Hypothesis:
During my investigation I am going to change the length the elastic band is stretched back and the weight of the carton. I predict the further back the elastic band is stored the bigger the distance the carton will travel once fired. In my second experiment I predict if I increase the weight of the carton it will lose distance.
Apparatus:
During my experiment I will use the following equipment:
Lab Stool
Elastic Band
Margarine Carton
Ruler
Weights
Safety:
I do not think that my investigation is particularly dangerous but if the margarine cartons are becoming hazardous I will take the necessary precaution such as goggles and making sure that nobody is in a dangerous position.
Method:
I will attach my elastic band to the bottom of the lab stool on two of its legs. I will then apply enough weight on the stool so it does not move and place the carton next to the band. I will the pull both the carton and the elastic band back at the same time when firing. I will measure how far I pull back the elastic band, how many Newton’s this is and how far the carton travels.
To keep my experiment a fair test I will keep the following things the same. The length of the unstretched elastic band will be 20cm and it will be placed 4cm above the floor when around the legs of the lab stool. I will try each of my experiments three times and take the average afterwards.
In the first experiment (when I am changing the length the elastic band is stretched back) the weight of the carton will always be 30.37g. I have added an additional 20g to the carton for optimum performance because without it the carton was too light and did not travel very well.
In my second experiment (when I am changing the weight of the carton) I will keep the length the elastic band stretched back at 11cm to make it a fair test.
Analysing Results:
From my experiment, I have found that if I increase the length an elastic band is stretched back it will increase the distance my margarine carton travels. If I increase the weight of the carton it will travel less.
I have drawn a line graph to show my results, I chose this because it has distance along the bottom and works well showing the gradual decline when increasing the weight. I have used the average of the three sets of results. At the start of the experiment (when there is no added weight) the carton travels the furthest but when extra weight is added it begins to travel less. The graph shows this very well because it starts off with a steep gradient up high and then decreases
My prediction was correct, when you increase the length the elastic band is stretched the carton is fired further. My second prediction was also correct because when more weight is added to the carton it travels less.
Evaluation:
I think the method I used worked well because I carried out my investigation efficiently and with good results. If I did my investigation again I would try to make my results even more accurate by using a ruler with more accurate measurements. I think my results were accurate but I could improve the accuracy by repeating the experiment over and over and taking the average.
If I had more time on this investigation I would try a number of different things. Firstly I would try changing some more variables such as the surface the carton travels on and the shape of it.