1. Limited time only! Sign up for a free 30min personal 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!

A problem of Cartesian diver

  1. Jun 11, 2010 #1

    I follow the instruction in wikipedia to make a Cartesian diver (Coca Cola bottle + eyedropper), and it works well. I press the bottle, the eyedropper sinks; I release, it floats.

    However, if I turn the bottle upside down, the eyedropper sinks and it never floats again. That means the buoyancy of the eyedropper is somewhat changed but I cannot understand the mechanism. If the buoyancy of the eyedropper decreases, the air pressure inside the bottle should increase, but it seems that it is not the case. I can open the bottle and the air pressure inside the bottle is equal to the atmospheric pressure, the eyedropper still sinks.

    Can anyone repeat the experiment and explain why it happens? Thank you!
  2. jcsd
  3. Jun 14, 2010 #2
    Perhaps some air came out of the dropper when you turned it around.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: A problem of Cartesian diver
  1. Cartesian diver (Replies: 2)

  2. Cartesian Diver (Replies: 1)

  3. Diver in ocean (Replies: 3)