Force= force is an agency (push or pull) that can change or tend to change the state of the body.
Inertia= is the property under any abject which holds its states of rest conditions or uniform motion of any object .
LAWS OF MOTION
Newton discuss these three basic laws of motion, which are given below:-
LAW OF INERTIA:-
These laws state that whenever a body is in a state of rest or uniform motion, it will remain in it until an external force is applied.
LAW OF FORCE:-
the law of force is defined as the force of any object as the rate of change of momentum of the particles. F=dp/DT where p=mv.
F=MA the unit of force kg m/sec2
LAWS OF ACTION REACTION
the law of action-reaction states that to energy action, there is always an opposite reaction
F 12 = F21
a force applied on one body due to second = forced applied on second due to first
IMPULSE:=
It is defined as the total effect of large force forms or acts for a short time to reduce a finite change in momentum. This is the product of force and evolution in time.
FRICTION:-
Whenever a body moves or tends to move over the surface of another body, a force comes into play that acts parallel to the surface of contact and opposes force is know as the motion of friction .
STATIC FRACTION
A force of friction that comes into play when between bodies before one body starts moving over the other is called static friction (fs )
LIMITING FRICTION
A force of friction between two bodies when the first body starts moving over the surface of another body.
this frictional force is called limiting friction. ( max ).
KINETIC FRICTION
A force of friction comes into play between two bodies when one body moving uniformly over the surface of another body. This friction is called kinetic or dynamic friction.
ANGLE OF REPOSE
The angle of repose is defined as the minimum angle that an inclined plane made with horizontal when a body paced on it . begins to slide down.
questions :-
A body of mass (m) is placed on the surface of the lift. find the value of apparent weight (r) in the following conditions
1 . lift moves upward with (a) acceleration.
F= MA
(R-MG) = MG
R= M (A+G)
2. Lift moves downwards with the same acceleration.
F = MA
(MG-R) = MA
R = M (G-A)
3. Lift moves upwards or downward with uniform velocity.
when lift moves upwards or downwards with uniform velocity (a = 0 )
from the 1st R = M (0+G)
4. Lift move downward under the action of gravity (freefall).
in case of the downward direction of lift under the action of gravity (a= g)
from 2nd (a=G )
R= M (G-A )
Some critical equation of friction ...
For safe tern the total frictional force should be greater or equal to applied centrifugal force
VMAX = ROOT MUE (R)(G)
About the neuton
once upon a time when neuton sitting in the shadows of apple trees he noticed that the apple fell on the ground, so he concluded that about gravity and also invented the laws which we learn today
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