Hey everyone, I'm new to physics forums and I would really like some help with my physics report. For my high school physics topic I have chosen an experiment where holes with differing diameters are drilled into the centre of the bottom of PVC pipe caps and the time taken for the each cap to fully submerge below the water line is recorded. Could someone help me with my overall understanding of the topic and how it may relate to Bernoulli's principle? 1. The problem statement, all variables and given/known data I've conducted the experiment and this is what I know: When the cap is dropped, the force weight is slightly larger than the buoyancy force and PVC is more dense than water. The buoyancy force upwards will result in water rushing through opening of the hole in the bottom of the cap. As the water rushes into the cap, the cap becomes heavier and consequentially the buoyant force is slightly smaller than the force of gravity on the cap because the PVC is more dense. Increasing the diameter of the hole size results in a higher flow rate as the larger the diameter of the hole is, the more liquid that will flow through it, that would otherwise be motionless at the bottom of the cap. Furthermore, smaller the hole is, the ratio of water touching the inside wall of the hole (and therefore at a zero velocity due to the no slip condition) to the water actually rushing through increases. Questions: Why does a higher flow rate decrease fluid pressure and how does this apply? What is the relationship between the liquid outside the cap and the liquid inside the cap? note: the water level is higher outside than inside Will the pressure of the water going through the hole change? Will the pressure due to the growing column of water on top play a role?