Hooke's law
presentation
By Yermekuly Ali
Let's remember:
What is the cause of all bodies falling to the
ground?
 Why do bodies thrown horizontally fall to the
ground?
 What kind of force is called gravity? How is it
designated?
 Why is the gravity at the poles somewhat greater
than at the equator?
 How does gravity depend on mass?
 How is gravity directed?

Why are bodies lying on a support or suspended by a
thread at rest?
Gravity acts on all bodies on Earth.
 As a result of gravity, a thrown stone, snowflakes, leaves
torn from branches, etc. fall to the Ground.
 The book lying on the table is also affected by gravity,
but the book does not fall through the table, but is at rest.
 Gravity is balanced by some other force.

Experiment
Put a kettlebell in the middle of a
horizontally placed board.
 Under the influence of gravity, the
weight moves down and bends the
board, i.e. the board is deformed.
 Conclusion: in addition to gravity
directed vertically downwards,
another force acts on the kettlebell.
 This force, directed vertically
upwards, balances the force of gravity.
 This force is called the elastic force.

The strength of elasticity
 The
force arising in the body as a result of
its deformation and striving to return the
body to its original position is called the
elastic force
 The elastic force is denoted by: Fupr.
Experiment






Let's hang the body on a spring. The spring is stretched.
An elastic force arises in the spring.
When the spring is stretched, the elastic force increases.
If the elastic force is equal to gravity, then the stretching stops.
The elastic force occurs when bodies are deformed.
If the deformations of bodies disappear, then the elastic force
will disappear.
The change in the length of the
body during stretching (or
compression) is directly
proportional to the modulus
of the elastic force.
Fупр. = k Δl
Δl- lengthening of the body
k – the proportionality coefficient,
which is called rigidity.
The rigidity of the body depends on
the shape and size of the body, as
well as on the material from which
it is made.
Hooke's law is valid only for elastic
deformation.
DEFORMATION
elastic

Deformation in
which the body
regains its shape after
the load is removed
plastic

Deformations that do
not disappear after the
cessation of external
influence
Graphic representation of the elastic force
N
Fs
Graph of the dependence of the elastic force on
elongation
F,H
3
2
1
0
l , м
The strength of elasticity
 The
combination of molecular forces is the
elastic force
 Occurs during deformation (one part is
displaced relative to the other)
 Two bodies at the same time
 Perpendicular to the surface
 Opposite in the direction of displacement
It should be remembered!
The force arising in the body as a result of its
deformation and striving to return the body to its
original position is called the elastic force
 If the deformations of bodies disappear, then the
elastic force will disappear.
 Types of deformation:
 Torsion; shear; bending;
 stretching; compression
