Equipment:- The equipment that I shall use will be a stopwatch; to make sure that the times are as accurate as possible, a table of which to stand on when dropping the cone, and sensible shoes whilst standing on the table, I will also have a metre rule to measure the 2m distance, from the floor to the bottom of the cone.
Method:- In this experiment I will time how long it takes for a cone to fall 2m. Each time I will make the cone slightly smaller, and therefore decreasing the surface area each time. I will then repeat each size three times: taking an average of the three times, of which I will then plot all the points on a graph. This will hopefully prove my prediction correct. The piece of card forming the cone will be moved 20° for each part of the experiment.
Variables:- Distance,
Surface area,
Weight.
The variable that I am going to change will be the surface area of the cone. This will help me determine whether or not my prediction is proven correct.
Fair Test:- To make this experiment a fair test, I will take an average of the times of the cone falling after repeating the experiment three times. I will also make sure that I move the piece of card forming the cone around 20° each time, making the surface area of the cone decrease in regular intervals.
Obtaining:-
Results:-
Analysis:-
My results show that the bigger the surface area of the cone the slower the cone would fall. This was due to the forces balancing out quicker. The smaller the surface area the quicker the cone would fall, it therefore takes longer for the forces to balance out, causing it to have a higher velocity.
Looking at the graph above you can see that it did take longer for the cone to fall with a larger surface area.
In the graph below you can see that the smaller the surface area the higher the velocity, (the time it took for the cone to fall in metres per second)
My results show that my prediction was correct, the smaller the area the faster the cone will fall. The terminal velocity only lasted for a couple of cm, as the forces balanced out quite quickly.
Velocity formula
Distance = Velocity
Time
Example:-
2 = 1.38
1.45
The larger the area the smaller the velocity, this is because it takes longer for the cone to reach the ground. The larger the area the more air resistance it encounters, this makes it fall slower to the ground.
My conclusion for this experiment is that the larger the area the longer it takes for the cone to fall, it therefore has a lower velocity. The smaller the area the quicker the cone falls, it also has a higher velocity.
Evaluation:-
The investigation I carried out was very good, as the results for each of the experiments that I carried out had almost the same time for each, the average was also very close to the time it took for each of the cones to fall. This data was very reliable.
There are not any results that don’t fit the pattern in the graphs.
To carry out this investigation I had to measure the height of 2 metres of which the cone would be dropped each time. These results were then recorded, and then I took the average of each result, and plotted these points on a graph. If I did this experiment again I would take more results of each area to make the averages even more accurate, and reliable data.
As well as having more data if this experiment was done again I would extend the experiment to involve weight. I would then try to prove that the weight of the cone would not affect the velocity and time of the cone falling. This would help me determine whether or not I was right about weight not being a factor of affecting the time and velocity.
If I was to do this then this would be my experiment then this would be what I would do:-
Prediction:- I predict that the weight would not make an impact on the time it takes for the cone to fall, and it’s velocity.
Equipment:- Plastacine
Stopwatch,
Metre rule,
Piece of card with cone and angles drawn on it.
This time the variable I would change would be the weight of the cone.
Method:-
I would drop the cone with a ball of plastercine in it from a height of 2m. Each time I drop it I would change the weight of the plastercine, repeating this three times each for each different weight, this way I could get an average of the times, making it even more accurate.
Acceleration and terminal velocity of falling cones.
By Ann Hitchcock
10DJG 10YH