- Submitted By: Weeeeeeeendy
- Date Submitted: 02/22/2016 3:59 AM
- Category: Science
- Words: 1066
- Page: 5

Deformation of solid

Hooke’s law

Explain force-extension graph

A

--Because we are changing the force and this

results in a change in the extension, the force

along the horizontal axis and the extension

along the vertical axis.

--But this graph has extension on the

horizontal axis and force on the vertical axis.

--Because the gradient of the straight section

of this graph turns out to be an important

quantity, known as the force constant of the

spring

--The extension x is directly proportional to

the applied force (load)

F = kx

Hooke’s low:

--A material obeys Hooke’s low if the

Extension produced in it is proportional

to the applied force (load).

--So, the force constant k of the spring is

given by the equation

k = F/x

--A stiffer spring will have a large value for

the force constant k. Beyond point A, the

graph is no longer a straight line; its gradient

changes and we can no longer use the

elastic limit & spring

constant

Elastic limit

--The force beyond which the spring becomes

permanently deformed is known as the elastic

limit.

--Explain: if you apply a small force to a spring and

then release it, it will return to its original length.

This behavior is described as ‘elastic.’ However, if

you apply a large force, the spring may not return

to its original length. It has become permanently

deformed

elastic limit & spring

constant

Spring constant

--Hooke’s low is a principle of

physics that state that the

force F needed to extend or

compress a spring by some

distance X is proportional to

that distance.

--F = kX, where the gradient k

is known as the force constant

of the spring

--F is the applied force (load)

--X is the extension

Calculation of the effective spring constant

of two spring combine in series

Consider two

springs placed

in series with a

mass on the

bottom of the

second. The

force is the

same on each

of the two

springs.

Therefore,

F = k11X11 = k22X22

Solving...