An Example being sky diving. When each jumper's turn comes, he or she takes a step away from the aircraft and begins free falling. Within 10 to 12 seconds, the jumper reaches terminal velocity, when the air resistance equals the pull of gravity. Average-sized skydivers fall at approximately 320 to 450 m (1050 to 1480 ft) every five seconds.
Prediction:
I predict that the cone’s speed will be proportional to the weight which is added to the cone, (number of paper clips).
This small sketch of a graph is what I am expecting to see when
I have the graph of my averages. (shown later in the project). The time that the cone takes will decrease as the weight is increased. Obviously from this I will also expect graphs showing the increase in speed.
Diagram:
Method:
Apparatus which is needed to carry out this investigation. You will need a Cone made from paper. The size that is determined in the Preliminary experiment. You will need simple apparatus in order to made the cone e.g. Compass and protractor (to determine the size of sector you cut out). You will also need two meter length rulers dependent on how high you are going to take readings from. A stopwatch will be needed to record the time of the cone falling.
I will be recording the time taken for the cone to reach the ground from a number off different heights to determine, when it starts and finishes traveling at Terminal Velocity. It is very important to keep what is measured constant, so it is a fair test. I will repeat the same readings a number of times and then take an average in order to get a more accurate result. This will minimize any mistakes made whilst recording the data. I will drop the cone from 265cm. Since in my preliminary experiment I proved to my-self that my cone was able to reach its terminal velocity I decided to raise the height from various heights to 265 cm. This was the highest possible height. I also doubled the diameter of the cone so it was able to hold more paper clips and would give a fairer test. Throughout the main experiment I would not alter with the streamline of the cone. This would make sure that the only variable was the weight, paper clips in the cone. To find out if the cone is traveling at its terminal velocity, we will divide the height by the time it takes to travel. Ofcourse I will only be using a stopwatch, so will be unable to record the data perfectly, therefor I have recorded all the data to two decimal places.
Preliminary Experiment:
I cut a 10cm diameter circle out of paper, then from that cut a 60-degree sector from the circle and made a cone. I then dropped the cone from 200cm, 150cm and 100cm, and recorded the time of the drop three times.
We were then able to work out is speed from these results, by using Speed = Dist/Time.
Speed measured in cm per second.
Results:
The above chart gives the results of my experiment, I recorded my data by increasing the number of paper clips by twos, and this let me have a wider range of results
These to Graphs are expressing my results in a easier way than on the chart above which was used to record the data in the experiment. They are both showing us the average of the 3 readings taken with the different amounts of paper clips.
GCSE, 25/10/01
GCSE SCI PRACTICAL
CHEMISTRY
by jonny boud
Evaluation:
First of all by looking at the data which has been put into graphs, you can see that the experiment has gone to plan apart from a few minor mistakes here and there.
As in my prediction,
“I predict that the cone’s speed will be proportional to the weight which is added to the cone, (number of paper clips).”
We are able to refer to the graphs of the average times and speed, we can safely conclude that as the weight is increasing the time taken for cone to fall is decreasing. Proportional to this is the gradual increase of the speed against the weight.
If all the data had been recorded to perfection you would be able to see how Terminal Velocity was present in this experiment. This all coincides with Newton’s laws of motions, explained in the theory.
In the speed graph there is a sudden increase in the results. There is no proven reason for this, apart from me amending the nose of the cone. Therefor the cone being more aerodynamic. The main evidence of success is taken from the first ¾ of the readings where there is a steady increase showing us a firm conclusion of Terminal velocity.
If I was to do this experiment again I would have not gone up in twos, so to get a more accurate graph of results, I would have found a way of recording the time more accurately.