Q.

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                        [2021]

1 β=0 when a=g2  
2 β>0 when a=g2  
3 β=2-12 when a=g2  
4 β=12 when a=g2  

Ans.

(1, 3)

P1=P2-ρ a cos45°d+ρ(g-asin45°)d

P1-P2ρgd=1-2ag

  β=0  for  a=g2

and    β=2-12  for  a=g2