Structures must be strong enough to withstand the force acting upon them
The shape, design and the materials used are all important in a structure
Structures are built by humans and other animals
EXAMPLE QUESTIONS
What do you think a ‘structure’ is?
What kinds of structures do you make use of every day?
What is it that makes a structure strong enough for the job?
STRUCTURES ARE BUILT FOR A PURPOSE
Structures are designed to do a particular job (for example, homes in which to live and bridges to cross over rivers).
STRUCTURES MUST BE STRONG ENOUGH TO DO THE JOB
All structures have to be strong enough to do the job for which they were designed.
They need to be strong enough to withstand any of the forces that will be applied to them.
THE STRENGTH OF A STRUCTURE DEPENDS UPON ITS DESIGN AND MATERIALS
Forces can change the shape of an object (for example, a hammer can change the shape of a piece of clay).
Structures need to be designed in a way that will ensure that they can withstand the forces that are likely to act upon them.
Two things are important here: first, the design of the structure, and second, the strength of the material, or materials, used to build the structure.
The most efficient structures are those which successfully combine design with material strength in an economic way.
HUMANS ARE NOT THE ONLY ANIMALS THAT BUILD STRUCTURES
Many animals have developed ways of making structures (for example, spiders build webs, birds build nests and beavers build dams).
These structures are strong enough for the job because of their designs, shapes and the materials from which they are made.
SOME STRUCTURES ARE NATURAL
There are many examples of natural structures that protect animals:
Eggshells are structures that protect unborn young
A tortoise has a protective shell, as do many molluscs and crustaceans
The skeleton of a human being, and other vertebrates, is a supporting structure
The structure of a tree has evolved to withstand the forces that act upon it
