Lab Report


Title: Comparing and Proving Archimede's Principle of Buoyancy

Problem Statement: Is Archimede's principle correct, in other words does the buoyant force equal the weight of the fluid displaced by an object? What is the buoyant force on the three objects (the weights and the neoprene wet suit) in the different fluids? How does this knowledge relate to diving?

Hypothesis: Our hypothesis is that Archimedes' principle is correct. We also believe that this principle relates to scuba diving as buoyancy is very important when diving, as it is the divers goal to maintain neutral buoyancy. By analyzing the results I believe we will find how neutral buoyancy can be maintained or is possible in all fluids. The buoyant force on the different objects, WHICH WAS MEASURED IN GRAMS, is expressed in the following charts:










Method and Materials: In order to discover the solution to our problem statement, the following materials are needed:
- One spill can
- One large graduate cylinder
- One 250 milliliter glass beaker
- One spring-scale
- One electronic scale
- One large Arrowhead bottle (the top cut off)
- Two steel weights
- One piece of neoprene wet suit
- 4400 milliliters of fresh water
- 4400 milliliters of salt water
- 4400 milliliters of vegetable oil
- 4400 milliliters of low-fat milk
- 4400 milliliters of Sprite

Before we began any testing, we weighed the 250 milliliter empty glass beaker. Next, we filled the spill-can with 880 milliliters of one of the six fluids (it was done one fluid at a time).Then, each of the three objects (one at a time again) was put on a spring scale and lowered into the fluid. The difference of the object's weight out of water and once in the water (the separate weights were expressed on the spring-scale) are recorded on the data table. This difference is the buoyant force on the object. To prove or assure that this is the correct force we weighed the displaced water (that spilled into the glass beaker). We subtracted the weight of the empty glass beaker we weighed in the beginning from this new weight. This difference is then recorded as another result of the buoyant force. The last time this process is done will be when testing the piece of wet suit in fresh water. In this situation, the spring scale will be held down (by my hand) to the bottom of the Arrowhead bottle. We can look at the spring scale and record the buoyant force pushing up. Next, we can place the piece of wet suit into a graduated cylinder and record the displaced water. After doing all the "experiment" works, we will be able to analyze the data and prove or explain the different points of our problem statement.




Analytic Essay


Conclusion: It has been proved, through our experiment, that Archimedes' Principle is corect. Also, by testing the principle in different fluids we were able to discover and prove that Archimedes' Principle is true in all fluids. By doing the experiment, we did get the buoyant force on the different objects, which are approximately correct. Through the experiment and gaining knowledge about buoyancy, it is apparent that buoyancy is important to divers. Staying at neutral buoyancy is optimal to divers. Also, by doing this experiment we can begin to discus the fact the by knowing a fluid's density a diver can figure out if they need more weight or an inrease of surface area (inflation of the BC) to stay at a neutral level of buoyancy.

 Background Information

Lab Report 

 Analytic Essay

 Display of Results







 St.Matthew's DEEP Website