(^64) Aptitude Test Problems in Physics
water in the vessel. The vessels are heated
to the boiling point of water and left to
cool. The time of cooling for the vessel
with the ball to the temperature of the
ambient is known to be k times as long as
the time of cooling for the vessel without a
ball.
Determine the ratio c b/c, of the specific
heats of the ball material and water.
2.29. Two identical thermally insulated
cylindrical calorimeters of height h=
75 cm are filled to one-third. The first calo-
rimeter is filled with ice formed as a result
of freezing water poured into it, and the
second is filled with water at T, =10 °C.
Water from the second calorimeter is poured
into the first one, and as a result it be-
comes to be filled to two-thirds. After the
temperature has been stabilized in the first
calorimeter, its level of water increases by
Ah = 0.5 cm. The density of ice is pice =
0.9pw, the latent heat of fusion of ice is
= 340 kJ/kg, the specific heat of ice is
C ice = 2.1 kJ/(kg•Ii), and the specific
heat of water is c, = 4.2 kJ/(kg.K).
Determine the initial temperature T ice
of ice in the first calorimeter.
2.30*. A mixture of equal masses of water
and ice(m = mw = mice = 1 kg) is con-
tained in a thermally insulated cylindrical
vessel under a light piston. The pressure on
the piston is slowly increased from the ini-
tial value Po = 105 Pa to p 1 = 2.5 X
106 Pa. The specific heats of water and
ice are cw = 4.2 kJ/(kg•Ii) and vice =
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