Section 4 Flashcards
When will a material deform
When there’s a pair of opposite forces acting on it
Hooke’s law
The extension of a wire is proportional to the force applied, assuming the elastic limit has not been exceeded
k
force constant
Nm-1
elastic limit
When the wire no longer follows hookes law and is permanently stretched
in series
half as stiff
in parallel
double k
Elastic deformation
When put under tension the atoms are pulled away from each other
The atoms can move slightly relative to their equilibrium position, without changing position and return back when the load is removed
plastic deformation
the atoms move position relative to one another and do not return to their original postions
tensile stress
force applied / cross sectional area
tensile strain
extension / original length
the greater the force the greater the __________?
stress
breaking stress
when the atoms separate completely and the material breaks
area under force/extension graph
elastic potential energy
how to work out elastic potential energy
E = 0.5 Fx E = 0.5 k x^2
Youngs modulus
stress/strain
