Fig.^53(^48) Aptitude Test Problems in Physics
The atmospheric pressure is Po = pm „gh,
where pm„ is the density of mercury, g
is the free-fall acceleration, and h is the
height. The length of each tube is 1> h.
What work A must be done by external
forces to slowly pull out the inner tube?
The pressure of mercury vapour and the
forces of adhesion between the material of the
tubes and mercury should be neglected.
1.103. Two cylinders with a horizontal
and a vertical axis respectively rest on a
horizontal surface. The cylinders are con-
nected at the lower parts through a thin
tube. The "horizontal" cylinder of radius r
is open at one end and has a piston in it
(Fig. 53). The "vertical" cylinder is open at
the top. The cylinders contain water which
completely fills the part of the horizontal
cylinder behind the piston and is at a cer-
tain level in the vertical cylinder.
Determine the level h of water in the ver-
tical cylinder at which the piston is in equi-
librium, neglecting friction.
1.104. An aluminium wire is wound on a
piece of cork of mass m —cork. The densities
Pcork, Pal, and py, of cork, aluminium, and