1. PF Contest - Win "Conquering the Physics GRE" book! Click Here to Enter
    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!

Fluids Question

  1. Apr 17, 2010 #1
    1. The problem statement, all variables and given/known data
    An object weighs 285 N in the air. When tied to a string, connected to a balance, and immersed in water, it weighs 230 N. When it is immersed in oil, it weighs 261 N.

    (a) Find the density of the object.

    (b) Find the density of the oil.
    2. Relevant equations


    3. The attempt at a solution

    this weight is equal to 285-230=55N corresponding to a density =1
    so the density of the body is 285/55=5.18

    the weight of oil is 285-261= 24 =Mgd(oil)
    compared to water d(oil)/d(water)=24/55=0.436
  2. jcsd
  3. Apr 17, 2010 #2
    Your answers are correct, but you should write down the units.
  4. Apr 18, 2010 #3
    I believe my answer is wrong. If someone would double check it.
  5. Apr 18, 2010 #4
    I did double check it when I first posted. Your answers are right but missing units. If your teacher wanted different units then perhaps therein lies your confusion.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Threads - Fluids Question Date
Business major... fluid dynamics question... Jan 6, 2018
Conceptual fluids question Dec 13, 2016
A Question on surface tension Nov 17, 2016
Fluid statics question Nov 6, 2016
Question for Syringe Feb 1, 2016