Page 96 - Physics
P. 96
Physics for Secondary Schools
Exercise 4.1 Applications of the concept of density
and relative density in everyday life
Answer all questions
1. (a) What is the volume of 2 400 kg Density and relative density has many
applications in everyday life, including the
of gasoline (petrol) if its following:
density is 0.7 g/cm ? 1. It aids in the identification of
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(b) Use the table below to answer gemstones such as gold and diamond.
the questions that follow. 2. Density is used by geologists and
mineralogists to determine the
Item Mass Length Width Height mineral content of a rock or other
(g) (cm) (cm) (cm) sample.
A 480 5 4 4 3. Density is considered during the
selection of building materials.
B 800 10 5 2 4. Density is also considered during
C 360 10 4 3 the design of swimming and diving
equipment.
D 600 5 4 2 5. Density is considered during design
of various marine and air vessels
(i) Which item is dense? so that they can fl oat. For example,
(ii) Which item is the least dense? aeroplanes are made up of aluminium
alloys and not steel. This is because
2. The water collected in a measuring the density of aluminium is less than
cylinder during an experiment using that of steel, thus, it is lighter than
a eureka can is 30 cm . When the steel. Moreover, aluminium is resistant
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object that displaced this volume to corrosion thus ensuring safety to
was dried and weighed, its mass the aeroplane and passengers. Figure
was found to be 90 g. Calculate its 4.10, shows an aeroplane made of
density. less dense material fl ying in the air.
3. A Form One student in Physics class
obtained the following results from
an experiment:
Mass of an empty beaker = 48 g
Mass of beaker + liquid M = 60 g
If she had used a 25 cm pipette
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to transfer liquid M to the beaker, Figure 4.10: An aeroplane
calculate the density of the liquid M. 6. Relative density can be used in
determining the density of an
4. What is relative density? Express unknown substance using the known
relative density in terms of mass. density of another substance.
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Student’s Book Form One
Physics Form 1 Final.indd 90 16/10/2024 20:56
