| Grade 8: Matter and Materials: Fluids |
|
Overall Expectations |
| •demonstrate an understanding of the properties (e.g.,
viscosity) and the buoyant force of fluids; |
| •investigate the buoyant force and other
properties (e.g., viscosity) of fluids, and design and construct pneumatic
or hydraulic systems that solve a problem in a given situation; |
| •describe how knowledge of the properties of fluids can
help us to understand and influence organisms in the natural world, and
to design and operate technological devices and to evaluate how efficiently
different devices make use of these properties. |
|
Specific Expectations |
| Understanding Basic Concepts |
| •compare various liquids in terms of their viscosity (e.g.,
water, syrup, oil, detergent, ketchup); |
| •compare qualitatively the densities of solids, liquids,
and gases; |
| •predict how the flow rate (an indicator of viscosity)
of different liquids is affected by temperature; |
| •describe qualitatively the relationship between mass
and weight (e.g., the mass of an object is constant but the weight of
an object varies as the pull of gravity on the object changes); |
| •describe qualitatively the relationship between viscosity
and density (e.g., with some exceptions, the greater the viscosity, the
greater the density); |
| •determine, through experimentation, the mass-to-volume
ratio of different amounts of the same substance (e.g., copper pennies); |
| •describe the relationship between the mass, volume, and
density of solids, liquids, and gases, using the particle theory; |
| •compare fluids in terms of their compressibility or incompressibility
(e.g., gases versus liquids); |
| •recognize and state the relationship between gravity
and buoyancy (e.g., without gravity there is no buoyancy); |
| •explain the effects of changes in temperature on the
density of solids, liquids, and gases, and relate their findings to the
particle model of matter; |
| •predict the effect of applying external pressure on the
behaviour of fluids; |
| •compare different liquids to determine how they alter
the buoyant force on a given object; |
| •compare liquids and air in terms of their efficiency
as transmitters of force in pneumatic and hydraulic devices. |
| Developing Skills of Inquiry, Design, and Communication |
| •design and build devices that use pneumatic
or hydraulic systems; |
| •design, make, and calibrate a hydrometer and use it to
compare the density of water with that of another liquid; |
| •design and construct a model of a common
device that uses pneumatic or hydraulic systems (e.g., dentist’s chair,
automobile hoist); |
| •formulate questions about and identify needs and problems
related to the properties of fluids, and explore possible answers and
solutions (e.g., design a fair test to determine whether oil, water, or
glycerol has the greatest viscosity); |
| •plan investigations for some of these answers and solutions,
identifying variables that need to be held constant to ensure a fair test
and identifying criteria for assessing solutions; |
| •use appropriate vocabulary, including correct science
and technology terminology, to communicate ideas, procedures, and results
(e.g., use terms such as flow rate, viscosity, compressibility, fluid,
density, pneumatics, hydraulics); |
| •compile qualitative and quantitative data gathered through
investigation in order to record and present results, using diagrams,
flow charts, frequency tables, graphs, and stem-and-leaf plots produced
by hand or with a computer (e.g., accurately measure and record the density
of different liquids using a hydrometer); |
| •communicate the procedures and results of investigations
for specific purposes and to specific audiences, using media works, written
notes and descriptions, charts, graphs, drawings, and oral presentations
(e.g., create a table to show the relationship between the buoyant force
and size of object); |
| •use the most appropriate items from
a selection of tools, equipment, and materials to perform a specific task
(e.g., use nuts and bolts to make temporary joints and screws to make
permanent joints; use a power sander for shaping and finishing); |
| •follow safe work procedures (e.g.,
check the condition of tools and equipment prior to using them). |
| Relating Science and Technology to the World Outside
the School |
| •describe situations in which the density of a substance
changes naturally (e.g., molten lava as it cools; air when mirages form)
or is intentionally altered (e.g., air in a hot-air balloon; cream when
it is churned and cooled); |
| •identify substances that are useful because of their
viscosity (e.g., sauces, vegetable oil, asphalt, hand lotion); |
| •compare the way fluids function in living things with
the way they function in manufactured devices (e.g., compare the human
circulatory system and a fuel pump); |
| •explain how the study of hydraulic systems enhances medical
knowledge about vascular systems (e.g., by clarifying how valves control
blood flow); |
| •describe some effects of technological
innovations related to hydraulics and pneumatics (e.g., getting water
from a tap rather than a well results in a reduced need for manual labour;
using automatic transmissions rather than mechanical linkages results
in greater efficiency); |
| •identify some design features (e.g., of aircraft, cars,
submarines) and explain how the design makes use of one or more of the
properties of fluids; |
| •identify industries in which the principles of fluid
dynamics play a central role (e.g., aeronautics, shipping). |