Detailed Plan
Equipment required : one pencil, compass, 1 piece of A4 paper, one pair of scissors , 25g of plastercene , a 2m ruler, a piece of cellotape, digital weighing scales and a stopwatch.
- Firstly, measure your compass to 15cm and draw a circle on the piece of paper.
- Then cut the circle out using a pair of scissors.
- Fold circle in half and in half again with a finger in the centre. A midpoint will appear after doing this.
- Use the fold lines of the circle to cut one slit, cutting up to the midpoint.
- Construct a cone out by moving the slit to a reasonable size. When happy with size, place the piece of cellotape on the slit so a cone is made.
- Weigh the plastercene so it is 5g and then 10g etc up to 25g. After using 5g measure 5g more and then add it on until you reach 25g.
- Now, place the piece of plastercene inside the cone (with the tip of the cone facing downwards).
- Hold the cone against the 2m ruler and drop it.
- Start the stopwatch and stop it once the cone has fallen to the ground.
- Record results in a table.
- Repeat the experiment 10 times for each mass (so a total of 50)
I will make sure that the experiment is conducted fairly as I will be dropping the cone from the same height each time. In addition, I will make sure the pieces of plastercene will be the same each time.
I will record my results into this table:-
Pilot Test
I am now going to construct a pilot test to test whether my method (detailed plan) works. In addition, I am going to carry the method out so I can see if I need to make changes to the plan.
After constructing a pilot test, I have come to the following conclusions to amend my detailed plan (method): I am no longer going to use a mass of up to 25g of plastercene in the experiment. Instead, I will use six masses, which will go up in 2g so they will be 2g, 4g, 6g, 8g, 10g, and 12g. I have altered the mass of plastercene because I found it difficult to record a result with the stopwatch as the cone went down too quick when 15g of plastercene was put into the cone. Therefore, if I use up to 25g of plastercene it will be impossible to record an accurate result. In addition, I am now going to use a clamp stand to keep the 2m ruler straight and still, which will mean that the height that the cone will is dropped from will be exactly 2m. I am going to measure the plastercene every time I repeat the experiment because the mass might alter when fallen down.
I am going to amend the results table by putting an extra column with the heading ‘averages’. I will be adding this extra heading because it will give a more accurate view, overall of the results I have obtained. I will lastly change the masses of the table which will be ‘0g, 2g, 4g, 6g, 8g, 10g, and 12g.
I have recorded these results after doing the experiment:-
Conclusion
My results from the graph show that when I kept adding 2g of plastercene to the cone the time decreased in a pattern. The pattern my graph shows is a curve, which is constant. If I had kept increasing 2g of plastercene, I am certain that the curve on the graph would straighten out. After doing this experiment, it is obvious that the initial prediction I made was indeed correct. I think that my prediction was particularly right because I used the idea that when the mass is larger the cone accelerates to a higher speed due to the terminal velocity being higher. Even though my graph shows one of the points distorted out of place the general pattern still shows. My prediction therefore backs up with the results I have obtained as shown in the graph. I think that the graph is in a curve because it shows the constant decrease in time after continuously adding more and more mass to the cone and the reason why it looks like it is almost going to straighten out is because the mass is so high that the results are starting to stay the same. This is due to their being a similar amount of force being pushed onto the cone.
Evaluation
I believe that the experiment I conducted was done accurately and carefully. My results show this as all the results on the table are practically identical. The average of each of the six masses shows this on the graph I drew. However, some results are inaccurate as shown on the graph and in the table of results. This is likely to be because I may have released the cone from a lower/higher distance than the required 2 meters, or I may have stopped the stopwatch too quickly/slowly. Generally, my results do support my conclusion as I believe that my results are reliable. Even though there is one point that does not go through the curve on the graph, I think that it is not an anomalous result because it is just marginally inaccurate and the point after it continues to fit the general pattern.
The method I used through the experiment was clear and easy to understand and go through. However, I think that I put too many points on the method which was not particularly necessary as this made my plan complicated. Also, I may have included too much detail, which may have extended the detailed plan a bit more than what was required.
I think that to make my results more accurate, I could get a series of people to carry out my method and record their results in a table. I would then take all the results and construct a graph identical to my one and compare them to my results. By doing this, it will be clear to see whether all the results I recorded are completely accurate. I believe that to obtain accurate results I need a solution so that every time I drop the cone it is at the same exact height each time. Also, the starting and stopping of the stopwatch also depends on how accurate my results are. To enable me to achieve these goals, I will have to use three people to do the experiment. This is because by allocating 1 person to drop the cone at the correct height, one person to start and stop the stopwatch and one person to record the results, there will be a far more accurate experiment.
To develop this investigation further, I could conduct an experiment of how the surface area of a parachute affects the speed. This will link with the investigation I have done because mass and surface area both affect the speed of a parachute. Also, I could get a range of different masses being dropped from a higher distance (e.g. 4 meters) and I could use heavier masses of plastercene and see the effects of the cone when the height is brought up and the mass is increased.
Mufaddal Inayathusein
