A closed container of water contains a Styrofoam block attached to the bottom of the container by a massless string. When the system is accelerated upwards, what happens to the tension in the string?
Background: I am an MCAT Physics teacher and this question was on an MCAT. Assuming the water is compressible, Newton's first law would indicate that a higher than normal pressure would result at the bottom of the container and a lower than normal pressure would result at the top of the container. The net result would be an increase in buoyant force (force due to a pressure gradient); thus, increasing the tension. The question I have is, "If the water were considered to be incompressible, would the tension still increase?"