Prediction
From the scientific information gathered and shown in my introduction, I can make these predictions;
- The more paperclips there are/the bigger the weight of an object - the greater the acceleration will be
This is based on the fact that, the heavier something is, the faster it will fall.
Variables
Focused Variable
For my experiment I will be focusing on the weight aspect. To do this I will be using paperclips as the added weight. The helicopter and paperclip weights will be noted.
Helicopter Weight = 0.8g
Paperclip Weight = 0.2g
Equipment
- Paper
- Pencil
- 15cm Ruler
- Scissors
- Metre Rule
- 0.2g Paperclips
- Stopwatch
Diagram
Experiment Safety
Care is needed when using scissors
Care is needed when reaching the heights to drop the helicopter
Preliminary Work
Before the main experiment, I will do my preliminary work. This will help me to find any problems and alter them for the proper test. It will also help me to decide the amount of paperclips to add each time and also the height at which the helicopter should fall.
For my preliminary experiment I will practice what I intend to do for real. I will make a mock up paper helicopter and drop it from a height, each time adding a paperclip to the end. I will drop the helicopter 3 times and work out the averages.
Preliminary Results
To work out the mean averages for these I will use the formula below;
Trial 1 + Trial 2 + Trial 3
3
Averages
As I was not using these results to graph I did not need to work out the speed
Main Method
I have decided from my preliminary work to;
- add 1x (0.2g) paperclip each time, this will give my results more range.
- drop the (0.8g) helicopter from 2 metres up, from this height the helicopter had enough time to spin before reaching the ground
I will drop the paper helicopter from a height and time how long it takes to reach the ground. On each drop I will add a paperclip to increase the weight. I will do this a number of times in order to produce an average. The results will be tabulated and then graphed to make my evaluations from. All tests will be repeated three times, and averages will be taken in order to rule out the possibility of anomalous results. All weights are recorded in grams (g) and time in seconds (s)
Fair Test
- I will use the same helicopter (at the same weight) throughout the experiment
- Finding averages from 3 tries will ensure a fairer test
- I will weigh the paperclips and make sure the weight is constant
- I will make sure that the tail of the helicopter is level with the top of the ruler every time – this way the helicopter will fall from the same height
Shown in the results will be both the number of paperclips and the weight of the helicopter each time (0.8g + 0.2g = 1g/1 paperclip added)
Results
This table shows the results I got from adding one paperclip at a time. I will use the three trials to find the averages. Following the formula below;
Trial 1 + Trial 2 + Trial 3
3
Averages
The average results were needed to be able to plot graphs.
From these results I will find the speed. I will use the formula below;
Speed = Distance (m) Time (s)
Results including speed
Graphs and Analysis
The trend shown in my graphs prove my prediction (The more paperclips there are/the bigger the weight of an object - the greater the acceleration will be) was correct.
Graph 1
The first graph shows us that there is a definite correlation (inverse) between the number of paperclips and the average time, showing that as more paperclips were added the less time it took to reach the ground from 2 metres. This proves my prediction.
Graph 2
The second graph is showing us that there is a positive correlation. This graph also helps to prove my prediction as it from it we can see that as more paperclips were added and the weight increased, the faster the helicopter went or the more speed (m/s)
For both of my graphs I would have expected the rate in which the time decreases to have kept at a constant.
Thinks that could affect the results
- Air Pressure
- Varied paperclip weights
Doors/windows opening or closing
- Height at which the helicopter is dropped
- Helicopter weight
- Type/thickness of paper used
- My reaction times (stopwatch)
Evaluating and Conclusion
I think that the procedure I used was reliable. The results I got were very reasonably accurate. There are a few things that can be altered in a future experiment to provide the more accurate, detailed evidence.
I learnt and was able to test the knowledge that terminal velocity is the maximum speed anything can reach when travelling and for this it involves the forces of acceleration and resistance being equalised.
From looking at my results you can see they are good because the line of best fit goes roughly through all of the result points. Also, the results fitted my prediction.
Improvements
If I was to do this experiment again there are a few things that I think could be changed or improved upon:
Light Gates could be used to improve accuracy. This way we would not be relying on the inaccuracy of my reactions
Trial Amounts. I could do more than 3 trials for each number of paperclips. I could get a better range from doing this and therefore get more accurate averages.
Something else I could have considered doing is that I could take the time from when terminal velocity occurs (when the wings start to spin) to when the helicopter hits the ground. Then I would be able to work out the acceleration with this equation;
Acceleration = Change in Velocity
Time Taken
This would make my evidence stronger and reduce the risk of any anomalies which affect the final conclusions.