1. Not finding help here? Sign up for a free 30min 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!

Archimedes' principle

  1. Mar 23, 2008 #1
    1.a piece of metal of weight 20gms has equal apparent weight with a piece of glass when both are suspended from the arms of a balance and immersed in water(density 1).if water is replaced by alcohol(density 0.96), 0.84gms must be added to the pan from which the metal is suspended to restore balance.what is the mass of the glass piece?

    2.a cube with each side of unit length has the same force F applied normally outwards on all its six faces.what are the expressions of longitudinal & volume strain in terms of the elastic modulii?
     
  2. jcsd
  3. Mar 23, 2008 #2

    tiny-tim

    User Avatar
    Science Advisor
    Homework Helper

    Welcome to PF!

    Hi soumya! Welcome to PF! :smile:

    You must tell us how far you've got, so that we know what's troubling you, and how to help.

    Start with the balance … what have you tried?

    What equations have you got? :smile:
     
  4. Mar 23, 2008 #3
    actually both prblms were in my class eleven's final Q paper.i have tried 1) as follows:
    1)let,
    mass of the glass piece=m gms
    In 1st case, apparent wt of metal=(20-20/d1),d1=density of the metal
    & apparent wt of glass=(m-m/d2),d2=density of the glass
    by the prblm,
    20-20/d1=m-m/d2..............(i)
    In case 2, apparent wt of metal=[20-(20+0.84)*0.96/d1]
    & apparent wt of glass=(m-m*0.96/d2)
    by the prblm,
    [20-(20.84*0.96)/d1]=(m-m*0.96/d2).............(ii)
    is this process write????????
     
  5. Mar 23, 2008 #4
    actually both prblms were in my class eleven's final Q paper.i have tried 1) as follows:
    1)let,
    mass of the glass piece=m gms
    In 1st case, apparent wt of metal=(20-20/d1),d1=density of the metal
    & apparent wt of glass=(m-m/d2),d2=density of the glass
    by the prblm,
    20-20/d1=m-m/d2..............(i)
    In case 2, apparent wt of metal=[20-(20+0.84)*0.96/d1]
    & apparent wt of glass=(m-m*0.96/d2)
    by the prblm,
    [20-(20.84*0.96)/d1]=(m-m*0.96/d2).............(ii)
    is this process write????????
     
  6. Mar 23, 2008 #5

    tiny-tim

    User Avatar
    Science Advisor
    Homework Helper

    No.

    (You understand, I can't give you the answer, I can only help you do it yourself? So …)

    20 is the mass of the metal, but d1 is the mass/volume of the water - so 20/d1 isn't anything.

    Start again. Do it one step at a time.

    First: what is Archimedes principle?

    How exactly does it reduce the weight of the metal? What does it depend on? Are there any unknowns?

    Same for the glass.

    What equation can you write? :smile:

    (How did you manage to post twice? :smile: If you click on "edit" under the second post, I think it gives you the option of deleting.)
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Archimedes' principle
  1. Archimede's Principle (Replies: 3)

  2. Archimedes Principle (Replies: 2)

  3. Archimedes' Principle (Replies: 3)

  4. Archimedes principle (Replies: 2)

Loading...