Pressure, Buoyant Force problem 8

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Homework Help Overview

The problem involves a beaker partially filled with water and a submerged piece of metal, focusing on the concepts of buoyant force and pressure. Participants are exploring how the scale reading changes when the metal is submerged in the water.

Discussion Character

  • Exploratory, Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • The original poster attempts to calculate the forces acting on the beaker and the submerged metal, questioning how to relate these forces to the scale reading. Some participants discuss the buoyant force acting on the metal and its implications for the scale's reading.

Discussion Status

Participants are actively engaging with the problem, with some offering insights into the relationship between buoyant force and the scale reading. There is a recognition of the forces at play, but no explicit consensus has been reached regarding the final answer.

Contextual Notes

Participants are working with specific values for density and volume, and there is an emphasis on understanding the implications of Newton's third law in this context. The original poster expresses uncertainty about their calculations and the next steps.

ChunkymonkeyI
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Homework Statement


When a beaker partially filled with water is placed on an accurate scale the scale reads 22.0 g. If a piece of metal with a density of 3.800 kg/dm^3 and volume of 2.40 cm^3 is suspended by a thin string so that the metal is submerged in the water does not rest at the bottom of the beaker, what does the scale read

Homework Equations


Density=m/v
F=mg
Fb=density of fluid times volume of fluid times g
Fb=F(bottom) minus F(top)
f(apparent)=F(weight) minus Fb

The Attempt at a Solution


First I used the beaker that was partially filled with water and tried solving for the force
F=mg
F=.0022kg times 9.80 m/s^2
F=0.02156 N

Then I Solved for force again with the density and volume given but then I just realize how does that help me so idk what 2 do please help me?
 
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the submerged piece of metal experiences an UPTHRUST equal to the weight of water displaced (2.4cm^3 is displaced) (density of water = 1gram/cm^3)
Newton's 3rd law tells you that every action(force) has a reaction(force) which is equal and in the opposite direction.
This means that the UPTHRUST must produce a 'downthrust' (my term... not a technical term)
Can you find what the balance will, read from this information?
 
technician said:
the submerged piece of metal experiences an UPTHRUST equal to the weight of water displaced (2.4cm^3 is displaced) (density of water = 1gram/cm^3)
Newton's 3rd law tells you that every action(force) has a reaction(force) which is equal and in the opposite direction.
This means that the UPTHRUST must produce a 'downthrust' (my term... not a technical term)
Can you find what the balance will, read from this information?

If I multiply the density of water by the volume of the object (1000 kg/m^3 times 2.4 times 10^-6) then I get a mass of 0.0024 kg and Ik the answer has to be 24.4 g so Idk what I am doing wrong
 
You have done it! 0.0024Kg is 2.4g. This is the Upthrust on the piece of metal and therefore the downthrust on the balance so the reading increases by 2.4g to give a reading of 24.4g
 
Wow omg thanks :)
 

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