Internal
are stresses, put on the materials that make up a structure.
Internal force
are stresses that act on a structure from outside it
External
a permanent force acting on a structure.
dead load
Steel has a high ______ strength
tensile strength
is wind blowing against a tree: live or dead?
live
can change the shape of a structure
Internal
Gravity is an example of what external force?
a changing or non-permanent force acting on a structure
live load
Rubber has high ______ strength
tensile strength
The mass of a container of shampoo is 256 g. Its weight would be ...
2.56 N
bend or tear a material by pressing different parts in different directions at the same time.
Shear force
What is the external load?
external forces act on a structure from the outside
A hurricane or tornado is an example of a force that can cause extreme damage to a structure when it acts on the structure, even for a short time. The environmental event is classified as a
live load
Rubber has _______ strength
torsion strength
Cross-country skis are designed to bend when a force is applied. Bending allows the middle of the ski to contact more snow, giving the skier a better grip when pushing off. The bending forces that are applied to the ‘camber’ (middle part of the ski) are ...
tension and compression
Bend a certain material, by pressing on different parts, in different directions, at the same time. The force you are creating is called
shear force
What external force caused the Tacoma Bridge to collapse?
wind
the weight of a bird in the tree
live
Tacoma Bridge Collapse had low _____ strength
The change in the shape or size of a structure can be due to internal forces which are produced by external forces acting on the structure and are called
deformation
When a solid material is compressed, small microscopic cracks in the material can enlarge or break apart. This can cause one section of the material to break away from the other part. This action is called ...
shear
True or False: Does external force include static and dynamic load?
true
the weight of the tree
dead
What has low shear strength?
graphite (lead)
the strength of a force refers to its ____.
magnitude