Analytic Essay

 Home Page Analytic Essay Animation Background Essay
Bibliography  Lab Report  Diagram Enhancements
Photos Links DEEP Website


If you to look at the other DEEP projects constructed by our classmates before viewing this one, you would notice that ours is slightly different. The reason is that all of our classmates' projects followed a certain law: Such as Charles, Henrys or Boles law. There were numerous amounts of experiments that could have been done which follow these laws. However, Grayson and I chose to construct our own experiment. We dropped a CD, a spike, a full soda can, and a rock. This experiment, though it seems very simple, proved many concepts. We were both fascinated with the concepts of drag, buoyancy, and resistance in water and air. So, we thought of an experiment that is explained in method and materials.

If you look at the results section of our lab, you will probably say something like: "of course," or "anybody can see that." This is because people already know it takes the objects longer to fall through water than it does in air. However, the real reason for our experiment was to decipher the question of why this happens. One of the reasons is this. Have you ever noticed that when you are in water as opposed to in air, you feel much lighter? This relates to the concept of buoyancy. According to Archimedes, "The buoyant force is equal to the weight of the displaced liquid." This means the more dense an object is, the more liquid it will push to the side of it, thus making it sink faster, or become less buoyant. you can see this proved in this picture:



Also, in the water things are more buoyant than in air. Objects which acquire a greater density do not float as well as objects with less density in both water and air. So, as displayed in our results, the objects with more density took much less time to hit the ground than the objects with less density. This is best displayed when comparing the results of the CD to the results of the full soda can. The CD, being much lighter, took a much greater time to hit the ground.

Another factor that contributed to the results we got was the concepts of aerodynamics and hydrodynamics. Aerodynamic is defined as an object that passes through the air easier than an object which is not aerodynamic. Hydrodynamic is defined as an object which passes through the water easier than an object that is not hydrodynamic. This is why the skinny spike, which you can see in the method and materials,took less time to hit the ground in both the air and water even if it didn't weigh as much as the full soda can, . The other extreme is the CD compared to the spike or anything else. Aside from the fact that it was also lighter than the other objects, it was much less aero and hydrodynamic. when it fell the air and water was caught under it and slowed it down.

The reason why we dropped the objects in the air instead of the water is because we wanted to make the times when we dropped in the air our control. For us to make any conclusions, we have to compare the results from the water drop to something. That thing is our results from dropping the objects in air.

Despite the fact that most of our results were pretty on the mark, and we got most of the information we needed, there was a great amount of room for error in this project. The biggest thing wrong with our project is that we relied on a stopwatch for all of our results. It is virtually impossible for a human being to stop and start a stopwatch consistantly and exactly when he/she is supposed to. This is why the same objects got different times for different trials. The reason we did three trials is so that we could take the average of all three and reduce the amount of error. You can see the percent of error for each object in air and water in the results section.Through this lab we have discovered the principles of drag, buoyancy, areo and hydrodynamics, and the percent and reasons for error in experiments. Overall this lab we constructed was very educational and lots of fun to do.