LA+Joe

Joe Franke March 20, 2009 Fire The effect of the dampness of the sand on the diameter of the crater. What is the effect of the dampness of sand on the diameter of the crater? Independent Variable- Dampness of sand Dependent Variable- Diameter of crater Constant Variables- Smoothness of sand, Height marble is dropped from, and Type of marble If the sand is dry then the marble will make a bigger crater because when the sand is wet it will be harder to penetrate. Diameter of craters For graph see attached sheet From our data we can infer that the dry sand with no water in it had the largest crater formed when the marble was dropped which was 5.7 cm. The sand with the 10 and 20 mL both had the same crater diameter of 3 cm and the sand with the 30 mL of water in it only had an average diameter of 2.7 cm. Based on all of our collected data we can conclude that our hypothesis was correct: If the sand is dry then the marble will make a bigger crater because when the sand is wet it will be harder to penetrate. This is correct because the more water we added, the harder it was for the marble to make a large crater because the sand was harder then it was when it was dry. Dry sand was our control in the experiment and the marble formed an average crater size of 5.7 cm. When we added 10mL to the sand the average size of the crater was only 3 cm. This was also the case with 20 mL of water. With 30 mL of water the average crater size was 2.7 cm proving to be the smallest. I trust my results because we made sure we were as accurate as possible and we tried to eliminate as many variables as we could. Some scientific forms of error are the sand was uneven some times; the marble was not dropped from exactly 40 cm the entire time, and the marble would, at some points, hit the ruler. All these things could have compromised our results in many ways. A new question that we could have investigated is “What is the effect of the size of the marble on the diameter of the?” I.V. Size of marble D.V. Diameter of crater C.V.- 1.) Dryness of sand.   2.) Height marble is dropped from. 3.) Amount of sand.   This concludes our experiment.
 * 1) Pour dry sand into container.
 * 2) Drop marble from 40 cm.
 * 3) Repeat last step twice more for a total of three trials.
 * 4) Add 10 mL to sand.
 * 5) Repeat steps 2 and 3.
 * 6) Add 10 more mL to sand for a total of 20 mL.
 * 7) Repeat steps 2 and 3.
 * 8) Add 10 more mL to sand for a total of 30 mL.
 * 9) Record all data.
 * Amount of water (in mL) ||  Trial 1  ||  Trial 2  ||  Trial 3  ||  Average  ||
 * Dry ||  6 cm  ||  5 cm  ||  6 cm  ||  5.7 cm  ||
 * 10 mL ||  3 cm  ||  3 cm  ||  3 cm  ||  3 cm  ||
 * 20 mL ||  3 cm  ||  3 cm  ||  3 cm  ||  3 cm  ||
 * 30 mL ||  2.5 cm  ||  2.5 cm  ||  3 cm  ||  2.7 cm  ||