A miniature cubic pressure probe with force sensors on all six faces is placed below…
PHYSICS · Single correct · AP · Physics 1: Algebra-based · Fluids · Fluids
Problem
A miniature cubic pressure probe with force sensors on all six faces is placed 2.0m below the surface of a large tank of water that is at rest. The probe is then slowly rotated about a vertical axis while remaining at the same location in the fluid.
Which statement best describes the sensor readings during the rotation?
(a) Faces that are perpendicular to the rotation axis register larger forces, while those parallel register smaller forces because the rotation produces centrifugal pressure differences.
(b) Horizontal faces show no change, but vertical faces register changing forces because only vertical faces are affected by the lateral hydrostatic pressure gradient.
(c) The force on every face remains constant throughout the rotation because fluid pressure at a point is the same in all directions.
(d) The forces vary with orientation because the hydrostatic pressure on a surface depends on the angle between that surface and the direction of gravity.