Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Weight of the boat in water.

  1. Oct 23, 2007 #1
    if i tell you that water displaced in terms of (Volume initial and Vfinal ) is Vf how would i be able (if you can) to calculate the weight of the boat?
     
  2. jcsd
  3. Oct 23, 2007 #2

    mgb_phys

    User Avatar
    Science Advisor
    Homework Helper

    If the boat is floating it's weight is equal to the weigth of the volume of water displaced.
    If you know the volume and density of the water you have the weight of the boat.
     
    Last edited: Oct 23, 2007
  4. Oct 23, 2007 #3
    Buoyancy has nothing to do with it?
     
  5. Oct 23, 2007 #4
    V_f would not allow you to know the weight of the boat, It would only allow you to know the volume of the boat. You must also know the material that the boat is made from in order to find the weight.

    The displaced water dictates how much upward force is exerted on the boat.
     
  6. Oct 23, 2007 #5

    russ_watters

    User Avatar

    Staff: Mentor

    That is buoyancy. That's what buoyancy is!
    http://en.wikipedia.org/wiki/Buoyancy
     
  7. Oct 23, 2007 #6

    russ_watters

    User Avatar

    Staff: Mentor

    No. Think about that a little more. Why would this tell you the volume of the boat? Most of the boat is not submerged! So the volume of water displaced is only the volume of the submerged portion of the boat....
    Yes, and....? How much upward force does the floor exert on you...?
     
  8. Oct 24, 2007 #7
    if order to do this we would need to find the height of the boat that is not submerged
     
  9. Oct 24, 2007 #8
    Sorry, I thougt that the implication was the the boat was fully submerged. My mistake.
     
  10. Oct 24, 2007 #9

    russ_watters

    User Avatar

    Staff: Mentor

    No, no, no, no, no.

    Look at the equation for buoyant force! You only need to know one thing (that isn't a constant) and you gave it in your opening post!
     
    Last edited: Oct 24, 2007
  11. Oct 24, 2007 #10

    russ_watters

    User Avatar

    Staff: Mentor

    A boat designed to run fully-submerged is called a "submarine"...

    A boat that is not designed to run fully-submerged but is must have a hole (or holes) in it, so it's sunken displacement tells you nothing about its weight or volume.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Weight of the boat in water.
  1. Changes in Water Weight (Replies: 15)

Loading...