1 00
Density and Buoyancy
38 A sample of liquid of density 0 85 g/ml weighs 32 3524 g in air with brass
weights What is the weight m vacua "
39 A platinum dish (D = 21 5 g/ml) weighs 65 2364 g in air with brass weights
What is the weight m vacua''
40 A crude brass weight of nominal value 100 g weighs 99 9986 g in air, with brass
weights What is its true weight in vacua''
41 A buret is calibrated by filling with water to the zero mark, withdrawing to the
25 ml mark, and weighing the water withdrawn From the following data,
compute the correction that must be applied at the 25 ml mark (similar corrections at other intervals may be used to construct a correction curve for the
entire range of the buret)
Final reading = 25 00 ml
Initial reading = 0 03 ml
Weight of flask + water delivered = 81 200 g
Weight of flask = 56 330 g
Temperature of water = 21 5°C
42 A geologist often measures the density of a mineral by mixing two dense
liquids, carbon tetrachlonde and acetylene tetrabromide, in such proportions
that the mineral grains will just float She then determines the density of the
liquid mixture, which is equal to the density of the solid When a sample of the
mixture in which calcite (calcium carbonate) just floats is put in a special
density bottle, the weight is 6 2753 g When empty, the bottle weighs 2 4631 g,
and when filled with water it weighs 3 5441 g What is the density of this
calcite sample
9 (The temperature of these measurements is 25°C )
43 How many pounds, including its own weight, can a hydrogen-filled balloon lift
in air if it is 50 0 ft m diameter
0 (The density of air is 1 205 g/hter and the
density of hydrogen is 0 0833 g/liter The lift is the difference between the
weight of the gas and that of an equal volume of air )
44 What percentage of your body (density approximately 1 03 g/ml) would be out
of the water while you floated on your back in Great Salt Lake (density of
water approximately 1 19
45 How far into a 2-mch cube of wood (density = 0 90 g/ml) must a 14 g iron
screw, i inch in diameter, be driven in order that the block will just float
9
(Assume that the block does not change in size when the screw is driven into
it The density of iron is 7 60 g/ml Assume that the density of water is 1 00
g/ml)
46 A "Cartesian diver is a hollow sealed bulb made of thin glass, such that the
overall density is just a little less than 1 g/ml As a consequence, it floats in
water If pressure is applied to the gas over the water in which the bulb floats,
the bulb collapses a little and then sinks When the pressure is released, it
expands and floats again A glass (density = 2 20 g/ml) sphere made on this
principle weighs 3 25 g
Density and Buoyancy
38 A sample of liquid of density 0 85 g/ml weighs 32 3524 g in air with brass
weights What is the weight m vacua "
39 A platinum dish (D = 21 5 g/ml) weighs 65 2364 g in air with brass weights
What is the weight m vacua''
40 A crude brass weight of nominal value 100 g weighs 99 9986 g in air, with brass
weights What is its true weight in vacua''
41 A buret is calibrated by filling with water to the zero mark, withdrawing to the
25 ml mark, and weighing the water withdrawn From the following data,
compute the correction that must be applied at the 25 ml mark (similar corrections at other intervals may be used to construct a correction curve for the
entire range of the buret)
Final reading = 25 00 ml
Initial reading = 0 03 ml
Weight of flask + water delivered = 81 200 g
Weight of flask = 56 330 g
Temperature of water = 21 5°C
42 A geologist often measures the density of a mineral by mixing two dense
liquids, carbon tetrachlonde and acetylene tetrabromide, in such proportions
that the mineral grains will just float She then determines the density of the
liquid mixture, which is equal to the density of the solid When a sample of the
mixture in which calcite (calcium carbonate) just floats is put in a special
density bottle, the weight is 6 2753 g When empty, the bottle weighs 2 4631 g,
and when filled with water it weighs 3 5441 g What is the density of this
calcite sample
9 (The temperature of these measurements is 25°C )
43 How many pounds, including its own weight, can a hydrogen-filled balloon lift
in air if it is 50 0 ft m diameter
0 (The density of air is 1 205 g/hter and the
density of hydrogen is 0 0833 g/liter The lift is the difference between the
weight of the gas and that of an equal volume of air )
44 What percentage of your body (density approximately 1 03 g/ml) would be out
of the water while you floated on your back in Great Salt Lake (density of
water approximately 1 19
45 How far into a 2-mch cube of wood (density = 0 90 g/ml) must a 14 g iron
screw, i inch in diameter, be driven in order that the block will just float
9
(Assume that the block does not change in size when the screw is driven into
it The density of iron is 7 60 g/ml Assume that the density of water is 1 00
g/ml)
46 A "Cartesian diver is a hollow sealed bulb made of thin glass, such that the
overall density is just a little less than 1 g/ml As a consequence, it floats in
water If pressure is applied to the gas over the water in which the bulb floats,
the bulb collapses a little and then sinks When the pressure is released, it
expands and floats again A glass (density = 2 20 g/ml) sphere made on this
principle weighs 3 25 g