| Grade 7: Structures and Mechanisms: Structural Strength and
Stability |
|
Overall
Expectations |
| •demonstrate an understanding of the relationship
between the effectiveness of structural forms and the forces that act
on and within them; |
| •design and make a variety of structures,
and investigate the relationship between the design and function of
these structures and the forces that act on them; |
| •demonstrate an understanding of the factors
(e.g., availability of resources) that must be considered in the designing
and making of products that meet a specific need. |
|
Specific
Expectations |
| Understanding Basic Concepts |
| •classify structures as solid (or mass)
structures (e.g., dams), frame structures (e.g., goal posts), or shell
structures (e.g., airplane wings); |
| •demonstrate awareness that the position
of the centre of gravity of a structure (e.g., bridge, building, tower)
determines whether the structure is stable or unstable; |
| •describe, using their observations, ways
in which different forces can affect the stability of a structure (e.g.,
certain forces may cause a structure to shear, twist, or buckle); |
| •demonstrate awareness that the effect of forces acting
on a structure under load depends on the magnitude, direction, and point
and plane of application of the forces; |
| •identify forces within a structure that
are affected by forces outside the structure (e.g., shear, torsion,
tension, and compression within a bridge are affected by external forces
such as high wind or ice); |
| •measure the performance of a structure (e.g., a bridge,
a tower) by comparing its mass with the mass of the load it
supports. |
| Developing Skills of Inquiry, Design, and
Communication |
| •use appropriate techniques and materials
(e.g., cutting and joining pieces of wood or plastic) while making structures
that have mechanisms; |
| •formulate questions about and identify
needs and problems related to the strength of structures, and explore
possible answers and solutions (e.g., determine what caused structural
failure and propose ways of supporting a specific load); |
| •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 fields, data, and cells when describing
databases); |
| •compile qualitative and quantitative
data gathered through investigation in order to record and present results,
using diagrams, flow charts, frequency tables, bar graphs, line graphs,
and stem-and-leaf plots produced by hand or with a computer (e.g., tabulate
data from tests of the strength of their own structures; record their
evaluations of possible solutions to a design problem); |
| •communicate the procedures and results
of investigations for specific purposes and to specific audiences, using
media works, written notes and descriptions, charts, drawings, and oral
presentations (e.g., create an animated film of the steps taken in designing
and making a product). |
| Relating Science and Technology to the World Outside
the School |
| •tell the “story” of a product used every day,
identifying the need it meets and describing its production, use, and
eventual disposal; |
| •investigate ways in which research is
done on existing products (e.g., basketball shoes, telephones) to generate
new ideas for the products; |
| •recognize the importance of researching needs and
opportunities for sale before proposing ways of developing a
product; |
| •recognize that a solution to a problem
may result in creating new problems in other areas, and that a solution
to a problem may be found while one is working on solving a problem
in another area; |
| •identify energy as a significant cost in the
manufacturing and use of products or systems; |
| •produce a work plan that outlines the
possible criteria for choosing resources for manufacturing a product
that they have designed (e.g., the properties and availability of the
resources; the aesthetic appeal of the product and the impact of its
use on the environment); |
| •describe, using their observations, the
function of symmetrical design in structural and mechanical systems
(e.g., in bridges); |
| •use their knowledge of materials in designing
and making structures that will stand up to stress; |
| •demonstrate how information is organized and stored in
a computer system (e.g., in a database or a spreadsheet
program). |
