2. What is Force?
A push or pull acting on the body is
known as force
3. Two types of force
Balanced Force
Unbalanced Force
4. Balanced Force
When two forces of equal magnitude
but acting in opposite directions on an
object simultaneously,then the object
continues in its state of rest or of
uniform motion in a straight line.such
forces acting on the object are known
as Balanced Force.
5. Unbalanced Force
When two forces of unequal
magnitudes act in opposite directions
on an object simultaneously,then the
object in the direction of large
force.These forces acting on the object
are known as Unbalanced Force.
6. Laws of motion
There are three laws of motion:1.First law of motion
2.Second law of motion
3.Third law of motion
7. First law of motion
According to this law everybody
continues in its state of rest or uniform
motion in a straight line unless
compelled by some external force
(i.e.unbalanced force) to change that
state.
8. Second law of motion
According to this law,the change in
momentum of a body per unit time is
directly proportional to the unbalanced
force acting on the body and the
change in momentum takes place in
the direction of unbalanced force on
the body.
9. Third law of motion
Action and reaction are equal and
opposite.
10. Inertia
The tendency of a body to oppose or
resist any change in its state of rest or
uniform motion is called inertia of the
body .
There are three types of Inertia:1.Inertia of Rest
2. Inertia of Motion
3. Inertia of Direction
11. Inertia of Rest
The tendency of a body to oppose any change in its
state of rest is known as inertia of rest.
Example:-When a tree is viourously shakensome of
the leaves fall from the trees.
When a tree is vigorously shaken,the branches of
the tree come in Motion but the leaves tend to
continue in their state of rest due to inerria of rest.As
aresult of this leaves get separated from the
branches of the tree and hence fall down
12. Inertia of Motion
The tendency of a body to oppose any change in its
state of uniform motion is known as inertia of
Motion.
Example:-The passengers fall forward when a fast
moving bus stops suddenly.
This is because,the lower part of the bodies of the
passengers come to rest as soon as the bus
stops.But the upper part of their bodies continue to
move forward due to inertia of motion.
13. Inertia of Direction
The tendency of a body to oppose any change in its
direction of motion is known as inertia of direction.
Example:-When a fast moving bus negotiate a curve
on the road, passengaers fall towards the centre of
the curved road.
This is due to the tendency of the passengers to
continue to move in a straight line.
14. Momentum
Momentum is nothing but product of
mass and velocity.
Momentum of fast running man is
more than that of running slow.