Properties of Matter

A cylindrical tube, with its base as shown in the figure, is filled with water. It is moving down with a constant acceleration a along a fixed inclined plane with angle θ=45∘.P1 and P2 are pressures at points 1 and 2 , respectively, located at the base of the tube. Let β=(P1 −P2)∕(ρgd), where ρ is density of water, d is the inner diameter of the tube and g is the acceleration due to gravity. Which of the following statement(s) is(are) correct?