An Investigation to find out how Dropping Height affects size of a Crater created by a Meteorite. Plan. The investigation is intended to demonstrate the way in which the size of a crater created by a meteorite is affected by the descent height. I will be using a Pleistocene ball as the meteorite. I shall be taking six readings starting with the size of the crater when the meteorite is dropped from 40cm above ground level, then the height will be increased each time by a further 40cm, until the final reading at 240cm.
Sand will be used in the impact area. To maintain a fair experiment I shall have to keep several variables at a constant. The mass and surface area of the meteorite and the force of gravity have all an affect on the force and speed that the meteorite hits the ground with, so I will have to keep these at a constant. I will keep the mass and surface area of the meteorite the same by simply using the same meteorite for reach reading. Since the force of gravity naturally stays at 9. 80N/kg, I do not need to attempt to control it.
Another set of variables I have to control and keep at a constant is the depth of the sand, the size of it’s container, and the it’s surface. This is to make sure that the sand reacts in the same way to each impact and is deep enough to contain the craters. I will keep the depth of the sand and size of it’s container a constant by simply using the same apparatus for each reading. After each reading is taken, then the surface of the sand will be levelled out to ensure the surface is the same for each impact. 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. Height 40cm 80cm 120cm 160cm 200cm Diameter 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.
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. Potential Energy = Mass ? Force of gravity ? Change in height J Kg N/kg m 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: Distance from ground level (cm) 40 80 120 160 200 240 Potential Energy (J) 3 Average volume of crater, excluding any anomalous results (cm3) 26. 2 36. 2 44. 5 54. 6 65. 4 74. 8 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.