what are the 3 ways the shape of an object can change?
stretching - forces in opposite direction away from the object
bending - forces that deform the object
compression - forces in opposite directions towards the object
what are the 2 types of deformation (change of shape)?
elastic and plastic
Elastic deformation occurs:
When objects return to their original shape when the stretching force is removed
Examples of materials that undergo elastic distortion are:
Rubber bands
Fabrics
Steel springs
Plastic Deformation
Plastic deformation occurs:
When objects remainstretched and do not return completely to their original shape even when the stretching force is removed
Examples of materials that undergo inelastic distortion are:
Plastic
Clay
Glass
The relationship between the extension of an elastic object and the force applied is defined by Hooke's Law
Hooke's Law states that:
The extension of an elastic object is directly proportional to the force applied, up to the limit of proportionality
The limit of proportionality is where if more force is added, the object may extend but will not return to its original shape when the force is removed (it will be inelastically distorted)
force = spring constant x extension
how is hooke's law represented in a graph?
a straight line
Linear and non-linear regions of a force-extension graph
A) linear
B) non linear
C) limit of proportionality
When a spring is stretched or compressed by a force, work is done by the spring
Work done is the transfer of energy
The energy is transferred to its elastic potential energy store
