Finding the density of a hydrogen proton

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SUMMARY

The discussion focuses on calculating the density of a proton, modeled as a sphere with a diameter of 2.4 femtometers (fm) and a mass of 1.67e-27 kilograms. The correct formula for density, D = m/v, was applied, but the user initially miscalculated the volume by using the diameter instead of the radius. The correct volume calculation should utilize a radius of 1.2 fm, leading to a density of approximately 2.3e17 kg/m³, which is significantly higher than the user's initial result.

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AryRezvani
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Homework Statement



A proton, which is the nucleus of a hydrogen atom, can be modeled as a sphere with a diameter of 2.4 fm and a mass of 1.67e-27 kg. Determine the density of the proton.

Homework Equations



As far as I know, the only required formula is D = m/v

The Attempt at a Solution



Well my attempt looks like this:

(2.4)^3*pi*(4/3) = 57.90583579 fm^3

Used google to convert that into kilometers, and got 57.905835791 (femtometer^3) = 5.79058358e-44 meter^3.

Divided 1.67e-27 kg by 5.79058358e-44 meter^3.

Got 2.883992566e16 but apparently, it's wrong.

Any suggestions guys?
 
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Hello, AryRezvani.

Note they give you the diameter, not the radius of the proton.
 
TSny said:
Hello, AryRezvani.

Note they give you the diameter, not the radius of the proton.

Ahh... Feeling rather stupid now.

Thanks.
 
That's not stupid, just a little oversight...(I'm doing things like that a lot in my old age :redface:).
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

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