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Archimedes Principle, Buoyant Force

  • Thread starter roman15
  • Start date
  • #1
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Homework Statement


Your local king has asked you to determine the density of a crown. If you suspend
it from a spring scale, the scale reads 8.33 N. If you then lower the statue into a tub of
water, so that it is completely submerged, the scale reads 7.81 N. What is the density
of the material from which the crown is made?


Homework Equations


buoyant force=pVg


The Attempt at a Solution


1.since the spring scale read 8.33N, i just used mg to find the mass of the crown, which is 0.85kg
2.since the scale read 7.81N when the crown was in the water, then the buoyant force is just the difference between its weight and the new scale reading,8.33N-7.81N right?
3. then i used Fb=pVg, where p is the density of the water and where V=mass of the crown/ density of the crown, then i just solved for the density of the crown. I got 16g/cm^3

is that right?
 

Answers and Replies

  • #2
gneill
Mentor
20,793
2,773

Homework Statement


Your local king has asked you to determine the density of a crown. If you suspend
it from a spring scale, the scale reads 8.33 N. If you then lower the statue into a tub of
water, so that it is completely submerged, the scale reads 7.81 N. What is the density
of the material from which the crown is made?
I don't know, but the statue is clean!

Homework Equations


buoyant force=pVg


The Attempt at a Solution


1.since the spring scale read 8.33N, i just used mg to find the mass of the crown, which is 0.85kg
2.since the scale read 7.81N when the crown was in the water, then the buoyant force is just the difference between its weight and the new scale reading,8.33N-7.81N right?
3. then i used Fb=pVg, where p is the density of the water and where V=mass of the crown/ density of the crown, then i just solved for the density of the crown. I got 16g/cm^3

is that right?
Looks good.
 

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