Archimede’s Principle

Lab Report #10

Archimede’s Principle

– Purpose, Equipment

– Procedure, Data

– Analysis

Group – Discussion

– Conclusion

Physics 2A

Professor Lilit Haroyan

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PURPOSE....................................................................................................................................... 3

EQUIPMENT................................................................................................................................. 3

PROCEDURE................................................................................................................................. 3

DATA ............................................................................................................................................ 4

ANALYSIS ................................................................................................................................ 5-6

DISCUSSION ................................................................................................................................ 7

CONCLUSION........................................................................................................................... 7-8

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The objective of this experiment is to investigate and test Archimedes’ principle by

directly measuring the buoyant force acting on a submerged object. Also, it was able to

determine the specific gravity for total 4 trials.

A balance was used to measure the weights and a metal block placing on this balance. A

container with an open spout was used to measure the weight. A beaker was used to contain

water and weight. An aluminum can was acted as a ship. Sand was used to measure the weight of

the ship and string was used to hold the metal block.

[Part 1] Verification of Archimede’s principle

The rod was held up the balance beam and a string was tied with the metal block on the

left side. The balance may not be calibrated yet, so calibrate the balance by making sure both

sides were equal. Once the balance was equalized, a 600 mL beaker that’s filled with water was

placed on the opposite side of the string. The block with the string was placed into the 600mL

beaker. Now that the balance was uneven again, some weights were placed to make the

adjustment with the balance. Most importantly, the block was completely submerged in the water

with the balanced weight in this procedure.

[Part 2] Predicting the Load of a “Ship”

A large beaker was filled up with water. The weight and height of a medium sized beaker

were measured and recorded in the lab notebook. A line should be drawn at the 6 cm mark of the

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medium sized beaker. An aluminum as the function of a ship was placed into the large beaker

and some weights were added into this ship until it was reached up to the 6 cm marker of the

beaker. This ship was removed from the water and measured how much weight was used to

cause the “ship” to sink. Sand was put into the cup until the “ship” was submerged into the 6cm

mark. Lastly, the weight of sand was measured.

[Part 1] Verification of Archimede’s principle

exp

Fb

(kg)

Wd

(kg)

th

Fb

(kg)

E

(%)

Trial 1 0.0904 0.0853 .0054 0.00547 0.00547 2.41%

Trial 2 0.0904 0.0820 .0084 0.00843 0.00843 0.36%

[Part 2] Predicting the Load of a “Ship”

H

(m)

Pw

(kg/m3

)

Wth

(kg)

Wexp

(kg)

Trial 1 0.04357 0.033 0.06 1000 0.1616 0.153 5.0%

Trial 2 0.04357 0.033 0.06 1000 0.1616 0.16019 0.87%

This table shows the data collected during the experiment. Weights were measured in

gram and converted to kilogram (kg). Height(h) and radius(r) was measured centimeter(cm) and

converted to meter (m). Pw was described in gram per cm3

and it was converted to kg/m3

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V. Analysis (Christian Dignos)

[Part 1] Verification of Archimede’s principle

For the verification of Archimede’s principle, the difference between the weight of the

metal block in air and its apparent weight in water is due to the buoyant force exerted on it by

water. The experimental buoyant force was calculated using the following formula:

The Theoretical buoyant force, on the other hand, was calculated by measuring the weight of the

water that is displaced when the metal block is placed on a can with an open spout. The volume

that the block occupies on the can will match the water that is displaced. According to the

Archimede’s principle, the water displaced , should be the buoyant force:

The weight of the open can was 15.45g, for which the displacement values are subtracted by to

find the weight of the displaced water.

These two values are then used to find the percent error of each individual trial by using:

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[Part 2] Predicting the Load of a “Ship”

For Predicting the load of the “ship”, The formula:

was used to find the theoretical load of the ship. For the purpose of this experiment, all the

values were converted to kg and meters for ease in calculation. Loading the values above into

this formula, the value for was found to be:

Trial 1 & 2: = (1000 kg/m)*(3.14)*(0.033^2)*(0.06m) - (.04357 kg) = 0.1616

The Experimental load, , was then found by weight of the sand loaded into the “ship” to the

point where the ship is buoyant to the 6.0 cm height. The weight of the sand and the ship is then

subtracted by the weight of the