Chapter 6 - Materials Flashcards
What is the name for forces that produce an extension in an object?
Tensile forces
What is the name for forces which compress an object?
Compressive forces
What happens to a spring when it experiences tensile and compressive forces?
Tensile deformation
Compressive deformation
What happens to the force-extension graph of a spring when it reaches its elastic limit? And what does the spring experience past this point?
It starts to flatten out and experience plastic deformation
What is elastic deformation?
When the shape of an object is deformed but it will still return to its original shape
What is plastic deformation?
When the shape of an object is deformed but it will not return to its original shape
When does a spring generally obey Hooke’s law?
When it has not yet reached its limit of proportionality.
What is the equation for force in terms of extension? (Hooke’s law)
Force = spring constant x extension
What is the spring constant of a spring actually measuring?
The stiffness of a spring
How can the spring constant be interpreted?
If the spring constant is high, the spring is difficult to extend
What is the gradient of a force - extension graph?
The spring constant
What happens to the work done on a material that is extended?
If it has not gone beyond its elastic limit, the work done on a material that is extended can be fully recovered
What is the equation for work done in a material that has been extended?
Change in W = Force x Change in distance
What is the area under a force - extension graph?
The work done on the spring
What is the work done on a spring in order to extend it transferred into?
Elastic potential energy within the spring