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!

Lifting using air presure

  1. Feb 10, 2010 #1
    1. The problem statement, all variables and given/known data
    * A blue whale is spraying out air in a vertical column every time it exhales.
    * The whale is exhaling a volumn V[air] = 6 m^3 of air in every blow at an initial speed of v[air] = 30 m/s. (The velocity is a guess.)
    * The diameter of the whale's blowhole is d = 0,2 m.
    (I am not sure whether of not I need some additional imformation.)

    Question: How fare up in the air h will a person of mass m[person] = 54 kg be lifted if this person is sitting on the back of a blue whale, right on top of the blowhole when the animal exhales?

    2. Relevant equations
    * The masse of the air: m[air] = V[air]*density[air]. (The air's density is found in a physics encyclopedia or similar, I assume).

    * The presure of the air when leaving the whale p[air]. (I probably have to use the air's velocity and mass in some way.)
    * In should probably be able to calculate at what height a person of mass 54 kg will be lifted, given the "lifting" presure p[air].

    3. The attempt at a solution
    <See 2. for my attempt.>
    Also, I have taken a look at http://en.wikipedia.org/wiki/Fluid_statics for some inspiration but it did not give me anything.
  2. jcsd
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted