Materials Flashcards
Define density?
Mass per unit volume
What is hooke’s law?
The force needed to stretch a spring is directly proportional to the extension of the spring from its natural length, up to the limit of proportionality.
What is the limit of proportionality?
The point beyond which force on a spring is no longer proportional to extension
What is the elastic limit?
The point beyond which a material suffers plastic deformation
What is meant by plastic deformation?
Permanent deformation or extension of a material
What does the gradient of a force against extension graph represent?
The spring constant,k
How do areas underneath stress- strain graphs differ from areas underneath force- extension graphs?
They are energies per unit volume.
What is a tensile force?
A force which stretches an objet
What is a compressive force?
A force which compresses an object
How can Young’s be found from a stress-strain graph?
Gradient of straight line section
Define yield stress?
The force per unit area at which the strain increases considerably for a no., or small increase in stress.
What is the UTS?
Ultimate tensile strength
The maximum stress the material can withstand
What is the density of water?
1000 kgm^-3
What happens to the spring constant of 2 identical springs in series?
Halves
What happens to the spring constant of 2 identical springs in parallel?
Doubles
