Doing experiment to find the authenticity of Archimedes' law

In summary, to show experimentally that Archimedes' principle is correct, you will need a newton-meter, a micrometer screw gauge, a metal cube of side 1 cm, and a beaker of water. Follow these steps:1. Measure the mass of the metal cube using the newton-meter.2. Using the micrometer screw gauge, measure the dimensions of the cube to determine its volume.3. Place the cube in the beaker of water and note the change in volume.4. Using the density of water, calculate the weight of water displaced by the cube.5. Subtract the weight of the cube from the weight of the water displaced to find the upthrust.6. Compare the calculated
  • #1
haha0p1
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Homework Statement
Describe how to use a newton-meter, a micrometer screw gauge, a metal cube of side 1 cm and a beaker of water to show experimentally that Archimedes' principle is correct. The density of water is known to be 1000kgm-³
Relevant Equations
F= pghA
I have solved the question like this:
Since Volume=Upthrust
We need to find the upthrust and the volume V. To find the volume, we will submerge the block in the water and find the difference.
To find the upthrust F, we will subtract the weight (finding the weight usinf newton-meter) from the upward force from the bottom of the block. Ergo, we will get the net upward force. Then we will compare value of Upward force F and Volume V. If the value is same, then the principle is correct.
Please tell whether this answer is right..
 
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  • #2
haha0p1 said:
Since Volume=Upthrust
Since when?
 
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  • #3
kuruman said:
Since when?
Since 246 BC...Archemedes' principle suggested that the Upthrust force is equal to the volume of water displaced by the object that is submerged.
 
  • #4
So if the volume of water displaced is 1 m3, the upthrust force is 1 N ?
 
  • #5
BvU said:
So if the volume of water displaced is 1 m3, the upthrust force is 1 N ?
Yes, it will equal 1 N.
 
  • #6
1. what about dimensions ?
2. No, it will not equal 1 N
 
  • #7
BvU said:
1. what about dimensions ?
2. No, it will not equal 1 N
Kindly explain why it will not equal 1N. I can't understand it
 
  • #8
1. Dimensions:

Upthrust is a force. Its unit is Newton. 1 Newton = 1 kg m/s2.

Volume has the unit m3

The mass of a volume ##V## of water is ##\rho V## kg (rho was given to you: 1000 kg/m3).
(check the dimensions: kg/m3 times m3 is kg).

The weight of a volume ##V## of water is ##\rho V g## N (##g## is 9.81 m/s2)
(check the dimensions: kg/m3 times m3 times m/s2 is kg m/s2).

2. Now, can you
haha0p1 said:
explain why it will not equal 1N.
?
 
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  • #9
haha0p1 said:
Since 246 BC...Archimedes' principle ... Upthrust force is equal to the volume ...

Check that, e.g. here !

##\ ##
 
  • #10
BvU said:
Check that, e.g. here !

##\ ##
Ohkok Now I got it. I was incorrect as I said that Upthrust is equal to the volume of water displaced. It was actually the weight of the water that was displaced!
 
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  • #11
haha0p1 said:
Ohkok Now I got it. I was incorrect as I said that Upthrust is equal to the volume of water displaced. It was actually the weight of the water that was displaced!
Yup.
 
  • #12
haha0p1 said:
Homework Statement:: Describe how to use a newton-meter, a micrometer screw gauge, a metal cube of side 1 cm and a beaker of water to show experimentally that Archimedes' principle is correct. The density of water is known to be 1000kgm-³
Relevant Equations:: F= pghA

I have solved the question like this:
Since Volume=Upthrust
We need to find the upthrust and the volume V. To find the volume, we will submerge the block in the water and find the difference.
The scale on the side of a beaker is not very accurate, especially for measuring small volume-changes. Why do you think a micrometer screw gauge is supplied?

haha0p1 said:
To find the upthrust F, we will subtract the weight (finding the weight usinf newton-meter) from the upward force from the bottom of the block.
EDIT: The upwards force is the upthrust. It is unclear what you actually do to find it.

haha0p1 said:
Ergo, we will get the net upward force.
It helps to define symbols for different quantities - then you can give a formula.

haha0p1 said:
Then we will compare value of Upward force F and Volume V. If the value is same, then the principle is correct.
That's wrong. See previous posts. You will need explain how to find the weight of water displaced.

General point: a good way to answer this sort of question is to give numbered steps. Each step is written as an instruction to someone, telling them exactly/clearly what they need to do.
 
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  • #13
Steve4Physics said:
That's wrong. See previous posts. You will need explain how to find the weight of water displaced.
In addition to that, if the purpose of the experiment is to verify Archimedes's principle as the title suggests, then you need to determine the "upthrust" independently and compare the two numbers. If they are equal to within experimental error, then the principle has been verified.

Providing a step-by-step experimental procedure as @Steve4Physics suggested is an excellent start. It will help us diagnose any problems in what you propose to do and the finished product will be your guide when you actually perform the experiment.
 
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  • #14

Related to Doing experiment to find the authenticity of Archimedes' law

What is Archimedes' law?

Archimedes' law, also known as the principle of buoyancy, states that any object submerged in a fluid experiences an upward force equal to the weight of the fluid displaced by the object. This principle helps explain why objects float or sink in water.

How can I design a basic experiment to test Archimedes' law?

A basic experiment to test Archimedes' law involves submerging an object in water and measuring the buoyant force. You can use a spring scale to measure the weight of the object in air and then measure the apparent weight of the object when it is fully submerged in water. The difference between these two weights gives the buoyant force, which should equal the weight of the water displaced by the object.

What materials are needed to perform an experiment on Archimedes' law?

To perform an experiment on Archimedes' law, you will need a few materials: a graduated cylinder or container filled with water, a spring scale, objects of known volume and weight (such as metal or plastic blocks), and a ruler or caliper to measure the dimensions of the objects.

How do I calculate the volume of water displaced by an object?

The volume of water displaced by an object can be calculated by measuring the increase in water level when the object is submerged. Alternatively, if the object has a regular shape, you can calculate its volume using geometric formulas (e.g., length × width × height for a rectangular block) and then use this volume to determine the weight of the water displaced.

What are potential sources of error in an experiment testing Archimedes' law?

Potential sources of error include inaccurate measurements of weight or volume, air bubbles sticking to the object, water temperature affecting density, and not fully submerging the object. Ensuring precise measurements and controlling variables can help minimize these errors and improve the accuracy of the experiment.

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