Jumping Jimminy investigation.

What am I going to investigate?

I am going to investigate the height to which a Jumping Jimminy will “jump” depending on how far the head and body (cotton reel) are pulled down when the stick is placed on a flat surface. I will also investigate some of the variables that will effect the height at which the jumping Jimminy will jump and the science behind the whole investigation.

Prediction.

My initial thought is that the more the “body” is pulled down the stick the greater the elastic potential energy will be so that when released the elastic potential will suddenly transferred into kinetic and sound energy resulting in it “jumping” in to the air. The more potential energy stored in the elastic band (by pulling the “body” down further) the more there will be transferred making it accelerating faster which results in it jumping higher. Some of the variables I can think of so far, that could effect the height at which it jumps would be the amount of elastic potential energy stored in the elastic band, another could be the amount of friction between the cotton reel and the stick in two ways 1:the longer the investigation goes on the more the stick gets worn down making it smoother so there would be less friction or 2: because the stick isn’t a “snug” fit in the hole in the cotton reel (there is room for the stick to move from side to side) when released, the cotton real could deflect and bounce from side to side up the stick resulting in more friction both of which would slow or increase it the transfer of the potential energy. Friction could also be present through the air particles (air resistance), which would also depending on the surface area of the J.J. could also slow it down but the surface area is so small that it wouldn’t make much difference.

Research.

For this investigation some of the key ideas and theories that would be helpful to now about and research for “behind” the scenes could be:

Friction: this is vague and could be applied to this investigation in many ways for starters it could be friction between the air particles and the JJ (air resistance) causing it to slow down but this would very much depend on the surface area of the JJ (but in this case it will be a constant variable). Another way could be friction between the base of the stick and the surface it is fired off of, if to little it could slip on firing and go off at a slight angle affecting its final height. One last way I can think of that friction could occur would be when the JJ is fired the body could scrape along the stick causing friction which would reduce the speed of the transfer of the elastic potential which would cause the JJ to jump slightly lower as more potential energy will also be lost to more sound energy.

Elastic:

when the body of the JJ is pulled down it stretches the elastic band storing elastic potential energy, if this is released slowly it will transfer to kinetic but at a slower pace but with more force if it is released fast it will produce more speed but with less force.

Robert Hooke, who in 1676 stated, The power of any springy body is in the same proportion with the extension.

Storing energy:

When an elastic band is stretched, a heavy flywheel turned, or a clock spring wound up, energy can be stored as ...

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Elastic:

Robert Hooke, who in 1676 stated, The power of any springy body is in the same proportion with the extension.

Storing energy:

When an elastic band is stretched, a heavy flywheel turned, or a clock spring wound up, energy can be stored as potential energy. Energy can also be stored in a battery or fuel as chemical energy and released when a chemical reaction takes place. Energy can also be saved as gravitational potential energy, such as when water is stored behind a dam and released to flow, turn turbines, and transfer energy into electrical energy.

Prediction

I think that there will be a correlation between the amount the JJ’s body is pulled down and the amount the JJ jumps up in to the air. I also think that during the test stage some erratic results might be obtained because it has many different variables that might sometimes produce “strange” jumps.

I think the results table might gently curve upwards because the more elastic potential energy stored when the elastic band is pulled down the more “power” transferred making it jump higher and higher so the graph will arc upwards. I have seen this in a previous investigation when I was testing the extension of springs (Hooks Law features heavily in this)

Apparatus

1Jumping Jimminy (cotton real, elastic band, wooden dowel, cello tape)

2 meter sticks

1 video camera

Method

After making the JJ I will use the same one through out to keep the test fair, the experiment will take place in front of a clearly marked meter stick so it can be see with the video camera, I will use a video camera to film the experiment so it can be played back lots of time in slow motion to get the results really accurate and to give evidence, the same person will “fire” the JJ so as to keep it as fair as pos. also to keep it as fair I will only change the independent variable and nothing else (the amount the body is pulled down) I will conduct the experiment with a range of evidence to be collected to be 10cm because after this point the JJ becomes very erotic and would be extremely hard to get reliable results. The dependent variables would be the size/length/thickness of the elastic band, the size/weight of the cotton real etc. I will conduct the experiment 4 times and then find the mean average so to get rid of in accurate or irregular results I will do the investigation 4 times because I think this is enough times to screen out inaccurate results but if I had more time I would have wanted to do this at least 2 more times.

Some of the methods for measuring the height that I have discounted (due to my preliminary investigations) would be I was planning to attach a piece of cotton to the bottom of the JJ then fire it and measure how much was pulled in to the air But in the preliminary tests I did I found out that the slight weight of the cotton was enough to pull it off to one side so the height wouldn’t be accurate, the other way I had first had the idea to do was to just watch the height by eye matching it to a meter rule behind but as I found quite obviously was this wasn’t accurate enough for the detail I want to go in to which is how I came to the video camera idea which makes it very accurate. This should provide the appropriate evidence needed to justify my prediction later on. This would produce a precision procedure to obtain an appropriate range of reliable evidence.

Results

2 marks

state simply what is shown by the evidence

4 marks

use simple diagrams, charts or graphs as a basis for explaining the evidence

Identify trends and patterns in the evidence

6 marks

contrast and use suitable diagrams, charts, graphs (with lines of best fit, where appropriate), or use numerical methods, to process evidence for a conclusion

draw a conclusion consistent with the evidence and explain it using scientific knowledge and understanding

8 marks

use detailed scientific knowledge and understanding to explain a valid conclusion drawn from processed evidence

explain the extent to which the conclusion supports the prediction if one has been made

Analysis

Plot a graph and explain in what it shows
Can mathematical patterns be identified?

Conclusion

I have based my conclusion on my results processed to give clear valid evidence. I feel it is valid because all my results are very close in each extension category and my graph has a very close fitting line of best fit also I only changed 1 variable at a time and my results were collected in a very accurate method. From looking at my graph I notice that at first the graph slowly arcs upwards which could be because the bonds between the particles are being stretched and separated but when the elastic band is stretched past 5cm the amount becomes very consistent and the line of best fit becomes almost straight this could be because the bonds of the particles have reached a point where they will spring back at the same pace where as at first before the 5cm mark they haven’t reached this point so the amount is proportional. In my plan I mentioned Hooks Law (double the extension double the height) this does not quite apply to my investigation but it is quite close, had I had time to continue with taking results this might have applied because I could have eliminated any anomalous results. Looking at my graph and results table I can see that none of my results were seriously anomalous but I had some that were more than 10cm different than the other results this could have been because of the way is was released, it could have stuck to the person releasing it’s fingers or they might not have let go as quickly as in previous tests.

Now looking at my prediction in one part I stated that I thought the graph would slowly arc upwards which is true but I hadn’t thought about the science behind it and the particles so in reality after gently arcing the graph almost completely straightened up it would have been interesting to see if the graphs line of best fit would have gone and arced back in to an “s” shape which is a familiar shape in maths and then a formula could possibly have had been worked out!

Evaluation

I think the procedure used was good using a video camera to see the height the JJ jumped with a meter stick behind so that when it was played back the exact height could be recorded and I then had good evidence for the height and if later on I found a big anomaly I had the opportunity to see what might have caused it and also as a double check so that the results were as accurate as pos. The only anomalies I had was some results were slightly different but not enough to be of serious problems these were just because of possibly the way they were launched, this could have been one of the main ways I could have improved the results collecting procedure some sought of release mechanism could have been made to eradicate the element of human error from the equation. Other than this I think the results were very reliable but getting rid of this final factor I think the results would have been very reliable. Again the way it was released could have been what caused the slight anomalies and this is the only factor I could think of that could have accounted for the slight anomalies one factor that didn’t effect it was the elastic band loosing its elasticity like in every day life having an elastic band in your hair it eventually loses its stretch the way I made sure this wasn’t happening was to not over stretch it, measure after each jump its length and if it was a factor the jumps would have been consistently lower than the previous test which they weren’t. Further work I would have liked to carry out on this investigation would have been to find a mathematical formula to work out any point I wanted to do. To carry that out I would have wanted to carry out more tests so the line of best fit would have been even more accurate so the formula and other work would have been even more accurate.