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!

Upthrust and weight

  1. Dec 6, 2015 #1


    User Avatar
    Gold Member

    1. The problem statement, all variables and given/known data
    Object immersed in fluid.
    If weight larger than upthrust, it sinks. If less, it floats. If weight equal to upthrust, it floats, right?

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
  3. Dec 6, 2015 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    That would constitute neutral buoyancy. In reality it could never quite happen (unless the object is a notional parcel of the fluid itself). It would not properly be described as either floating or sinking. It would just stay wherever it is put, as long as it is fully immersed. It could be touching the surface, touching the floor, or anywhere in between.
  4. Dec 6, 2015 #3


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    If by 'upthrust' you mean buoyancy, the terms 'positive buoyancy', 'negative buoyancy', and 'neutral buoyancy' have specific meanings in this context.

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

Have something to add?
Draft saved Draft deleted

Similar Threads - Upthrust weight Date
Calculating upthrust of float May 6, 2017
Question about the upthrust of a rocket Dec 25, 2016
Upthrust/ how does the weight of a sphere change in water? Jan 4, 2016
Origin of upthrust Sep 16, 2015
Buoyancy, upthrust Feb 13, 2015