Our teacher had us come up with our own thermodynamics experiments, so I put a glass of water inside a vacuum-capsule. Inside the glass of water I have placed a non-floating object, a small plastic ball. If I enable the vacuum, the water will begin to develop bubbles of vapor. Those bubbles attach themselves to the plastic ball and it floats.
What I want to figure out now, is how I can approximate the amount of bubbles that are necessary to lift the object. Also, does the vacuum make it easier to lift it, as the pressure on the water surface is lower?