Internal Forces
What is an internal force
Force that acts on a structure from within
What is an external force? give an example
Forces that act on an object due to some other object ie wind
What is a structure?
something made of many parts that is put together to serve a purpose.
What is gravity?
the force that pulls everything towards the earth's centre
What is Symmetry?
Structure is made up of the same parts, so that one side is the same as the other side
What is a pushing internal force?
Compression
What is the term used to describe how much force is acting on a structure?
Magnitude
What is the difference between form and function?
Form- how the materials or parts are organized in order to serve the function
Function- structures purpose
Form follows Function- When we make a structure we need to understand the function of the structure before we build it
T or F the taller the building the more difficult it is for engineers to make it stable and not fall over?
True
What is Aesthetics?
The study of beauty, attractiveness and taste. Symmetry=Aesthetically Pleasing
What is tension? Give an example
Tension is a pulling force. Example an elastic
What is a net force?
tells us how much force is acting on a structure
What is a shell structure? Give two examples
Has a strong layer on the outside that holds itself up. They are usually curved and relatively thin, allowing space on the inside.
Examples: coconut shells, mugs, igloos, basketballs, and tin cans
What is centre of gravity?
it is an imaginary point on a structure where the weight og the structure is evenly dispersed around it.
T or F it is easier to find the center of gravity in asymmetrical structures?
False
What is a shear force? Give example
happens when there are two opposing forces acting on the same structure.
Example opening a bag of chips, using scissors
What is a point of application?
describes where the force strikes on the structure
What is a solid structure? Give two examples
has no space inside and is usually made on one solid material
examples rocks, bricks, ice
Why does the Tower of Pisa Lean?
The soft ground shifted the soil, which destabilized the towers foundation. The soail underneath is made of clay, fine sand, and shells which creates too soft of a foundation for such a heavy structure.
T or F Asymmetrical structures allow forces acting on them to be balanced.
False
What is the twisting force that is applied to a structure? Give one example
Torsion example twisting a wet towel
T or F Natural disasters are weak external forces
False
What is a frame structure? Give two examples
structure that has a combination of horizontal beams and vertical columns that form a skeleton that can be covered or open
examples: buildings, spider webs, trees, bicycles, and bridges
T or F keeping the centre of gravity as low as possible will decrease its stability
False
Why do engineers use symmetry in structures?
Structures are stronger, and to make them more aesthetically appealing