(a)
if we assume that the vacuum cleaner functions as a high vacuum pump and produces zero
pressure inside the house
the air below the brick will then exert a net upward force of
F = P A
= P (π rhose2)
= (1.013 x 105 Pa) [π(1.43 x 10-2 m)2]
= ....... N
(b)
in this case the octopus can pull the bottom away from the topn shell with a force that could be
no larger than
so we get
F = P A
= (Po + ρ g h) A
= [(1.013 x 105 Pa) + (1030 kg / m3) (9.80 m / s2) (32.3 m)] [π (1.43 x 10-2 m)2]
= .......... N