1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Density and Boyancy

  1. Nov 19, 2009 #1
    1. The problem statement, all variables and given/known data

    apparent mass of the metal weight in air = 100g
    apparent mass of the metal weight in water = 75g

    a)Compute the buoyancy force. From this, compute the volume of the metal. Compute the density of the metal. The density of aluminum is 2.7 g/cm3, of iron is 7.9 g/cm3, and of gold is 19.3g/cm3. Is your metal mostly aluminum, iron, or gold?



    b)The mass of a plastic sphere is 110g. Calculate the buoyancy force and use it as above to compute the
    density.

    3. The attempt at a solution
    F bouyancy = density water * vmetal*g
    Fbouyancy = Mdw*g

    Fbouyancy = (Mmetal in air - Mmetal in water)
    Fbouyancy =( 100-75)(9.8) = 245g*m/s^2
    F bouyancy = density water * vmetal*g
    245g*m/s^2 = 1g/cm^3 *Vmteal*9.8m/s^2
    Vmetal = 25cm^3
    p = m/v
    p = (100g/25cm^3)
    p=4g/cm^3
    I not too sure if this is correct.....
    I dont know how to do part b)
     
    Last edited: Nov 19, 2009
  2. jcsd
  3. Nov 19, 2009 #2

    ehild

    User Avatar
    Homework Helper
    Gold Member

    Your result is correct.

    ehild
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Density and Boyancy
  1. Boyancy Problem (Replies: 6)

  2. Air Boyancy Question (Replies: 4)

  3. Boyancy project help (Replies: 4)

  4. Basic Boyancy problem (Replies: 4)

Loading...