Quote:
Originally Posted by Rusty
If you can answer this easy physics question than I'll agree that you are the "greatest" thinker known to mankind:
A block of hardwood is floating easily on the surface of a lake. As a storm approaches, the density and pressure of the air above the lake begin to decrease. As a result of this decrease in air pressure and density, the block of wood
(C) moves downward slightly and floats lower in the water.
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The log is buoyed up by the sum of two forces, the weight of the water displaced and the weight of the air displaced. Together they equal the weight of the log. With the weight of the now lower pressure air reduced, the log sinks ever so slightly. The buoyant force of the air displaced is further reduced because the volume of air displaced is reduced by this sinking, while the buoyant force of the water is increased due to more of it being displaced. One could calculate the increase in depth if given the densities of the log, water, and air before and after the pressure change. A bigger challenge would be to determine how to measure such a tiny change in immersion.