Forces
A push or pull that tends to cause an object to change its movement or shape
What is a force
All structures on earth must be able to resist this force pulling on them
What is the force of gravity
Is an external force, has two types
What is load
Forces that act within a structure
What is an internal structure
A strong rigid shape that cannot be bent
What is a triangle
3 things that affect the force of a structure
What is magnitude, direction, and location
A force that is applied on a structure by something else
What is an external force
The weight of the structure and the non-moving load it supports, also known as dead load
What is static load
A force that acts to stretch or pull apart something
What is Tension
Results when internal and external forces are applied to a structure which can weaken it
What is structural stress
Three ways to classify structures
Solid, Shell, Fram
The amount of matter in an object
What is mass
An external force that moves or changes with time, also known as live load
What is dynamic load
A force that acts on an object or pushes parts together within an object
What is compression
Is a framework of beams joined together. Usually, in the form of interlocking triangles
What is a truss
Stability is . . .
The ability of a structure to maintain position, balance, and shape--> even when forces like wind, gravity, and weight act on it
The imaginary point in an object where the downward force of gravity acts
What is centre of gravity
Why don't cars have perfectly rigid frames?
To enhance passenger safety through crumple zones, which absorb collision energy, preventing it from transferring to occupants.
A force which push parts which are in contact with each other in opposite directions
What is shear
Choosing the right material often involves considering pros and cons. Steel is stronger than other materials such as wood, but it is also heavier. How can you solve this problem?
Beams in the shape of an I, an L, a T, or a box have less mass than solid beams but are not weaker. They help to distribute weight.
Why do football players use a three point stance?
To widen their base and lover their centre of gravity
A balanced arrangement of mass that occurs on opposite sides of a line or plane, or around a centre of axis
What is symmetry
Explain why gravity is considered an external force.
An external force is a force that acts on an object from outside the object.
Gravity pulls objects toward the Earth, but it does not come from inside the object itself. The pull comes from the Earth.
For example:
Because gravity acts on objects from the outside, it is an external force.
Name 5 real life examples of internal forces.
Scissors cutting, a suspension bridge cable, a guitar string, or a stretched elastic band, a bookshelf sagging under heavy books, wringing a wet towel or a car's axle rotating
Results when a structure can no longer stand up to the forces acting on it