Method
I will use a 14.5 cm cone of paper, that has been selected using my preliminary work, this size was selected due to the fact that is didn’t flutter and traveled in a straight line. It will be dropped from a height. I will wait for the cone to reach terminal velocity and start timing at a measured height of 3.74m. I will take the time for the falling object to reach the ground, using a stopwatch, and record the data in a table. I will repeat this experiment 3 times and do the experiment for different weights. Keeping my parachute the same I will increase the weights by 5g each time.
Fair Test
I will not change the timing person, stopwatch, cone, person dropping cone. The only thing I will change will be the chosen variable, which is weight. I will also repeat each experiment 3 times and take an average of my results; this is to ensure that my results are accurate, and count out any anomalies.
Prediction
I predict that if I increase the weight of a falling object then the terminal velocity will increase. I believe this because if the weight increases then eventually the air resistance will equal it. This results in the object accelerating and when the two forces are equal it is at its terminal velocity.
If I double the weight then the air resistance will double. The object will move twice as fast hitting twice as many molecules, this will then cause the object to slow down twice as much. It will do this until the air resistance equals the weight and it reaches terminal velocity.
Results
Analysis
I have generally found out that when weight is increased terminal velocity increases; there is a vague trend that as u increase the mass by 5g the velocity increases by 1m/s. The theory behind this is that the speed is greater for the falling of the heavier cone because it requires a higher speed in order for the force of friction to cancel out the weight. The amount of air resistance depends upon the speed of the falling object. The cones with the different masses will continue to speed up until the encounter an amount of air resistance, which is equal to their weight. Since the heavier cones weigh more, they will travel to higher speeds before reaching a terminal velocity. Therefore the more massive objects fall faster because a larger force of gravity acts them upon, for this reason they speed up until the air resistance force equals the gravitational force.
Evaluation
I think the procedure used was an accurate way of getting the results I needed, but for further experimentation I wouldn’t use a cone because it isn’t the most accurate of things, as if flutters slightly, and where is it heavier on one side due to the glue holding it together, I tended to drift slightly. The quality of my results should be good as:
- The same person started and stopped the stopwatch each time.
- The experiment was repeated twice for each mass.
- The same cone was used for each experiment.
- Nothing was changed except for the chosen variable.
- The cone was dropped and given a time to reach terminal velocity before the stopwatch was started.
In my results I didn’t get any anomalies.
The way the procedure was carried out was the best that could be done with the resources available. The recordings I took were not exact but they were reliable enough to determine if the prediction was correct or not and make a good conclusion.
By Shaun Gilchrist
