Will the scuba diver sink or float

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Homework Help Overview

The discussion revolves around a scuba diver's buoyancy, specifically whether she will sink or float based on her mass and the volume of water displaced by her gear. The problem involves concepts from fluid mechanics and buoyancy.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the calculation of the buoyant force using Archimedes' principle and question the conversion of volume from liters to cubic meters. There is also a focus on the weight of the displaced water and its implications for buoyancy.

Discussion Status

Some participants have raised concerns about the accuracy of the volume conversion and the resulting buoyant force calculation. There is ongoing exploration of the assumptions regarding the type of water (salt or fresh) and its density, which may affect the calculations.

Contextual Notes

Participants note the importance of significant figures and the context of the problem, including the type of water, which could influence the density used in calculations.

rmiller70015
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Homework Statement


A scuba diver and her gear displace a volume of 65.0L and have a total mass of 68.0kg. What is the buoyant force on her and will the diver float or sink.


Homework Equations



FB=pFVg

The Attempt at a Solution


The first thing I did was find the weight of the diver as w=mg=68.0kgX9.8m/s2=670N
Then I tried to find the buoyant force using archemedes' principal (FB=pH20Vg
I used the given density as 103 kg/m3, the volume of water displaced is 65.0L, which I converted to m3 by using the factor of 103L/1m3 to get 6.5X104m3. The equation then becomes
(103kg/m3)(6.5X104m3)(9.8m/s2)
and I get 6.4X108N, which is greater than mg, so the diver would float.

I'm wondering if this is correct or not

Edit: Forgot to mention, I'm not too concerned with sigfigs, as long as the answer is withing a reasonable variance the teacher will give me credit.
 
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That buoyant force is awfully large. Check your L to m^3 conversion
 
rmiller70015 said:

Homework Statement


A scuba diver and her gear displace a volume of 65.0L and have a total mass of 68.0kg. What is the buoyant force on her and will the diver float or sink.


Homework Equations



FB=pFVg

The Attempt at a Solution


The first thing I did was find the weight of the diver as w=mg=68.0kgX9.8m/s2=670N
Then I tried to find the buoyant force using archemedes' principal (FB=pH20Vg
I used the given density as 103 kg/m3, the volume of water displaced is 65.0L, which I converted to m3 by using the factor of 103L/1m3 to get 6.5X104m3. The equation then becomes
(103kg/m3)(6.5X104m3)(9.8m/s2)
and I get 6.4X108N, which is greater than mg, so the diver would float.

I'm wondering if this is correct or not

Edit: Forgot to mention, I'm not too concerned with sigfigs, as long as the answer is withing a reasonable variance the teacher will give me credit.

How much does 65L of water weigh?
 
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Salt water, or fresh water?

Not that it matters much in this case, but it matters when you dive.
 
Borek said:
Salt water, or fresh water?

Not that it matters much in this case, but it matters when you dive.

Good point! :smile:
 
If there are 1000 L in 1 m^3, how can 65 L = 65000 m^3?

That's the amount of water displaced by a large ship.
 

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