What is the correct density of the cork based on its buoyancy and weight?

  • Thread starter Thread starter awertag
  • Start date Start date
  • Tags Tags
    Buoyancy Density
Click For Summary
SUMMARY

The discussion focuses on calculating the density of cork based on its buoyancy and weight. The cork weighs 0.224 N in air and 0.672 N when submerged, leading to a buoyant force (Fb) calculation of -0.448 N. The user initially calculated the density as 5000 kg/m³, which was incorrect. The correct approach involves reevaluating the buoyant force and ensuring accurate calculations of mass and volume.

PREREQUISITES
  • Understanding of buoyancy and Archimedes' principle
  • Basic knowledge of weight and force calculations
  • Familiarity with density formulas (density = mass/volume)
  • Ability to perform unit conversions (N to kg and m³)
NEXT STEPS
  • Review Archimedes' principle and its application in buoyancy problems
  • Learn about calculating buoyant force in fluid mechanics
  • Study the relationship between weight, mass, and gravitational force
  • Practice density calculations with various materials and conditions
USEFUL FOR

Students studying physics, particularly those focusing on fluid mechanics, as well as educators seeking to clarify concepts related to buoyancy and density calculations.

awertag
Messages
63
Reaction score
0

Homework Statement



A large piece of cork weighs 0.224 N in air. When held submerged underwater by a spring scale as shown in Figure 13-27, the spring scale reads 0.672 N. Find the density of the cork.

Homework Equations



Fb=buoyant force

The Attempt at a Solution


i found mass by doing .224/9.8 so mass=2.286e-2 kg
then i got Fb by doing weight in air minus weight in water so Fb=-.448 N
then i did Fb=(densitywater)(volumeobject)(g) and got the volume of object so volume=4.571e-5 cubic m
last i did density=mass/volume and got the incorrect answer of 5000 kg/cubic meter

If anyone can help me, I don't know where I went wrong. Thanks very much, awe.g
 
Last edited:
Physics news on Phys.org
What's an Fb when it's at home? There's no attached figure.
 
what do you mean at home? sorry I am confused
 
idk if that's what you want...justr a picture, doesn't show much though
 

Attachments

  • 13_27.gif
    13_27.gif
    15.4 KB · Views: 527
awertag said:
what do you mean at home? sorry I am confused

Sorry, it's just an expression. Take a look at the directions that the forces act, and re-evaluate your value for Fb.
 
oh ok lol. what does the expression mean exactly? Like originally?

and would Fb be equal to mg?
 
The expression is an inquiry as to what something (or someone) really is.

Fb is the force of buoyancy. It's opposing the weight of the object. Check your calculation for Fb.
 

Similar threads

How many people can be on the raft?
  • · Replies 10 ·
Replies
10
Views
1K
What Is the Connection Between Buoyancy and Apparent Mass?
  • · Replies 2 ·
Replies
2
Views
2K
Aluminium weight buoyancy problem
  • · Replies 2 ·
Replies
2
Views
3K
What is the spring's length and constant in Hooke's law with buoyancy force?
  • · Replies 2 ·
Replies
2
Views
2K
Yes, that makes sense. Thank you for pointing that out.
  • · Replies 8 ·
Replies
8
Views
2K
How Large Must a Helium Balloon Be to Achieve Neutral Buoyancy?
  • · Replies 3 ·
Replies
3
Views
4K
Density of Liquid: 1667.7kg/m^3 | Solving Buoyancy Q.
  • · Replies 8 ·
Replies
8
Views
3K
Buoyancy and Archimedes Principle, volume ratio/density question
  • · Replies 5 ·
Replies
5
Views
4K
Modeling a kongming lantern (sky lantern)
  • · Replies 6 ·
Replies
6
Views
3K
What is the Apparent Weight of an Iron Block Submerged in Water?
  • · Replies 6 ·
Replies
6
Views
6K