This is the apparatus I will be using:
Prediction
I predict that the higher the dropping point, the larger the crater made upon impact. This is because the higher the meteorite has to fall, the longer it has before impact, and so the longer it has to accelerate, and the more kinetic energy it can build up. Since energy cannot be created or destroyed, all this kinetic energy has to be transferred to something else upon impact when the meteorite is forced to stop moving. The energy will be transferred to/absorbed by the sand. This creates the crater. Therefore, the more kinetic energy the meteorite has upon impact, the more energy the sand has to absorb, and so the bigger the crater.
Trial experiment.
During my trial experiment, I discovered is it important that the sand is dry and not wet, this way the crater that in made is a more of a cone shape, whereas in wet sand the crater is a section of a sphere:
This way the volume of the cone can be worked out, which gives an approximate volume of the crater.
volume of a cone=π r²d/3 (where r= radius, and d=depth)
ResultsThese are the readings I took:
I have used πr²d/3 as a formula to work out the approximate volume of the craters.
Analysis
My results show that when the meteorite was dropped from 40cm, on average it made a 26.2cm3 crater, from 80cm a 36.2 cm3 crater, from 120cm a 44.5 cm3, from 160cm a 54.6 cm3 crater, from 200cm a 65.4 cm3 crater, and finally from 240cm a 74.8 cm3 crater.
My first graph shows like I predicted, that as the dropping height increases, so does the size of the crater. In fact, it shows that for every 4cm above ground level the dropping height is, 1cm3 of sand is removed upon impact, leaving a crater. This is because height affects the potential energy of an object.
The potential energy of an object is the energy that it can to convert into other types of energy. In this case, the potential energy of the meteorite is converted into kinetic energy in the sand, making a crater. The more potential energy the meteorite has, the more energy has to be converted into kinetic energy in the sand, and the more kinetic energy in the sand, the larger the crater.
The potential energy of the meteorites were as follows:
My second graph shows that for every 100cm above ground level the meteorite is dropped from it gains a further Joule of Potential energy.
Evaluation.
My experiment did prove that as Dropping Height increases, so does the volume of crater, though it is not completely reliable. My data contained several anomalous results, such as the approximate volume of the crater when the meteorite fell from 200cm in set 2 is nearly 8cm3 larger then the average volume at that height. Unreliable anomalous data such as this could have been recorded due to errors in several main areas:
Due to human error, the dropping height may have been measured inaccurately and/or there may have been inaccuracies when measuring the diameter and depth of the craters.
Also, it is probable that the sand was not perfectly levelled for each impact, which may have lead to it reacting differently to each impact, making different size craters.
In addition the mass of the meteorite was not kept at a constant: each time it came into contact with the sand, some sand stuck to it’s surface. This will have had little affect on the results, but it should not be dismissed.
I did repeat the experiment for each height five times in an attempt to ensure that the data is reliable and not just a fluke, but to accurately discover the effect of dropping height on the size of a meteorite crater I should really repeat the experiment as many times as possible. This would compensate for any anomalous results.
