4.5.3 Forces And Elasticity Flashcards
examples of forces involved in stretching, bending or compressing an object
- elastic potential energy
- thermal energy
explain why, to change the shape of an object (by stretching, bending or compressing) more than one force has to be applied
for stretching, bending or compressing - two or more forces have to act in opposite directions (balanced)
describe the difference between elastic deformation and inelastic deformation caused by stretching forces.
inelastic deformation is the point when elastic is stretched so far that it doesn’t go back to its original shape. whereas elastic is when an object doesn’t go back to its original shape when the forces are removed
the extension of an elastic object, such as a spring is what ?
directly proportional to the force applied, provided that the limit of proportionality is not exceeded.
Force equation
Force = spring constant x extension (F = k e )
Force unit
Force, F, in newtons, N
Spring constant unit
Spring constant, k, in newtons per metre, N/m
Extension unit
Extension, e, in metres, m
A force that stretches (or compresses) a spring does what ?
It does work and elastic potential energy is stored in the string. Provided the spring Is not inelastically deformed, the work done on the spring and the elastic potential energy stored are equal
What is the difference between a linear and non-linear relationship between force and extension ?
When an elastic object is stretched beyond its elastic limit, the object does not return to its original length when the force is removed. In this instance, the relationship between force and extension changes from being linear to being non-linear.
What is the equation used to calculate work done in stretching (or compressing) a spring (up to the limit of proportionality)
Elastic potential energy = 0.5 x spring constant x (extension)^2
