Equipment-
- Wooden ramp
- Books to prop up the ramp
- Metre ruler
- Plastic tubing x2
Method-
Take the ramp and prop it up using some books. Use a metre ruler to measure the height, and record this to the nearest centimetre. Draw a line on the ramp so you know where to hold the tube and don’t hold it over the line. Gently let go of the tubing, but make sure you don’t push it, if you do it will gain more energy and make it an unfair test. Wait and see where it stops. Measure to this point from the line of release you have drawn with the metre ruler and record. Repeat twice for one height and record all results even if they don’t look right. Do this test twice for each of the different heights (test about 5 different heights). Also change the circumference of the tube afterwards but do the experiment as before and record in a different table, making sure you clearly state what weight the tube was, and see whether the circumference of the tube affects the distance rolled.
Accuracy-
My experiment will be a fair test as the tube will be the same throughout, keeping mass constant, as will the book surface and the ramp. I will also make my measurements as accurate as possible by using a metre ruler at all times to measure any necessary distances and also I will read them and record the with accuracy. The surface of the ramp may affect the outcome of the results because any type of grip on the surface could slow it down and also such things as lubricants on the ramp could make the ramp slippery in effect speeding up the tube.
Repeats-
For each experiment I will repeat it three times but also make sure that I also record any strange results that occur in the process. I will do this for a variety of consistent heights, making sure they go up in the same amount each time. Like I mentioned in the method I would use two different weight tubes, this will also tell me whether the distance travelled is affected by the weight of the tube.
Safety-
Safety is not a key element in this experiment, accidents may be caused by carelessness and lack of attention, such as knocking the stand onto someone’s toe, and I will be extra-vigilant to avoid these things occurring.
Fair testing-
I will keep these variables the same throughout the experiment otherwise it would be classed as an unfair test. The experiment will be a fair test as there will only be two variable factors: the height of the ramp and the weight of tube, but I will only use two different weight tubes. All the other factors will stay the same such as the material used for the ramp this means that there will not be any bias issues in this experiment.
If these were not abided by the experiment would be classed as an unfair test as none of the results would be the same, also you would not be able to make tables and graphs out of them. You also need to be consistent in the height, a bad thing to do would be to do it a 3cm then 7cm then 11cm. You should make sure they go up in 5’s or 2’s and so on. Also with changing the weight of the tube you have to be careful as you cannot go too mad and do loads of different weights a couple of variables for the weight is fine.
Obtaining Evidence – Changes to my plan-
When I did my investigation I did not need to change anything, on the surface I rolled it onto which ended up to be carpet as it rolled too far on a smooth surface. But apart from that due to my careful planning I did not need to change my plan in anyway, shape or form.
Results-
Analysis-
My graph for the guttering roller is great, it goes up steadily and I have got most of the points into the graph. From looking at the results it is clear that both my aim and predictions were achieved and that the prediction was correct. I believe that this was only achieved due to the careful planning and thought put into it before I attempted to start the experiment. My graph has taken this shape because I carefully measured everything, for obvious reasons I could not be 100% accurate due to the fact that I did not measure everything to the nearest millimeter due to the fact that it is totally impossible to do that. The hardest bit the measure though was the drop off of the ramp onto the floor, but I think I was successful. Although the graph for the smaller tube was not as good as the graph for the guttering I believe that it was ok. Also I didn’t think that the smaller tube’s distance traveled would decrease, but it did. My graph for the guttering agrees with my predictive graph in that it goes up gradually and that it doesn’t start at zero. Along with this the guttering follows the whole concept of science shown in the background section. My second graph disagrees with the above information, as the graph is the total opposite, and also it goes against what I said the background information section. I did expect it to follow the background information section and also I expected the graph to be the same, only that it started lower and went. I thought that it would a line underneath the line for the guttering but this was not the case in this instance.
Evaluation- My prediction was proved correct as the graph for the guttering clearly show that the speed does indeed increase when the ramp is raised higher. This is due to the fact that more potential energy is given to the tube as it is raised higher. So the higher an object goes, the more gravitational potential energy it gains. When it falls, it’s potential energy is converted into kinetic energy and; since energy can neither be created or destroyed, only converted; it will move at a faster speed. I found my method easy to carry out as I wrote it in simple steps. I think that my method could be improved by adding a few more steps, and bullet pointing them instead of putting them in a paragraph. As I knew what I was doing but a stranger may not be able to follow it if it’s in a paragraph. I could get extra evidence by doing extra heights, testing two different surfaces, one a flat smooth floor and the other a carpet, and test even more circumference tubes, as you would be able to get a better idea. But that would not be possible in a school environment due to the fact there is not enough space, the only two spaces you could do it on are the tennis courts and the astro-turf. This extra evidence will help me to paint a bigger picture as to the factors affecting the distance travelled by different tubes down different heights. I would like extra evidence to prove that the smaller tube’s results were either wrong or right, this is because I am being a bit weary as to whether they are correct, as they seem to not tally up with any known scientific queries. I did not have that many anomalous results just a few results that were not on the line, which I don’t think are anything to worry drastically about. My anomalies results were probably caused by carelessness when I was performing the experiment. I will be extra vigilant to prevent this re-occurring next time. I believe in the end my results showed a clear pattern even though there were a few factors affecting them as I mentioned above.