Laws of Motion | Newton's Three Law of Motion

laws of motion newton three laws of motion in the past before newton baba scientists believe that there is only one natural state of any object for example consider this ball at the rest scientists believe that this is the natural state of the ball secondly consider this car at the rest scientists believe that this is the natural state of the car on the other hand scientists believe that objects stay in motion only if they are pushed or pulled but eventually the moving body would come to rest which is the natural state of any object let me

repeat it scientists believe that objects stay in motion only if they are pulled or pushed but eventually the moving body would come to rest which is the natural state of any object in conclusion they thought that everything in the universe is in the natural state of rest our every moving object and the universe would eventually come to its natural state of rest this concept of natural state of rest was totally wrong and it was rejected later newton baba came who presented three laws of motion now what is the first law of motion well we can

easily understand newton's first law of motion if we divide it into two parts firstly newton bubba states that every object has two natural states either it will remain in a state of race or it will remain in a state of uniform motion note down that in uniform motion the net external force on object is always zero or we say that f is equal to zero now consider this ball at the rest according to newton baba this state of rest is the natural state of the ball secondly consider this car that this car is moving in

a straight line with uniform speed according to newton baba this uniform speed or uniform motion of this car is also natural state secondly newton baba states that if you want to change natural state of any object you need external force or unbalanced force for example consider the ball at the rest when you kick this ball you exert external force on the ball as a result of this you change the state of rest and the ball starts moving after covering some distance the ball will stop here let me ask you what is stopping the ball well

the answer is simple the friction force of the ground is stopping the ball if we eliminate the friction force of the ground the ball will continue its state of motion forever secondly consider this moving car when you suddenly apply brakes you exert force on the car and you change the state of uniform motion of the car as a result of this the car stops therefore newton barbara states that a body in rest or uniform motion will remain in its natural state unless acted upon by external force remember that if a body is a natural state

the net force on the body is always equal to zero some very talented people and very famous book write f is equal to zero personally i do not like this i always write net force is equal to zero secondly we can also say that if net force on a body is zero a body will remain in its natural state of rest or uniform motion just noted down these important points about newton's first law now let me teach you the application of newton's first law in everyday life consider some books present on the table we know

that these books are experiencing the downward force of the gravity that this is 10 newton force at the same time the table is exerting upward force on the box that this is also 10 newton force now let me ask you what about the net force on the box well the net force on the box is zero so we say that these books are at rest which is the natural state of the books secondly consider the jumping of a paratrooper we know that this person is experiencing the downward force of the earth that the downward force

on this person is 500 newton also we know that at the same time the air resistance is pulling this person in upward direction let this upward force is also 500 newton now let me ask you what about the net force well the net force is 0 newton but we know that this person is still in uniform motion or it is moving with uniform speed towards the earth here a lot of students are confused they think that if the net force is zero then why the paratrooper is moving with uniform speed towards the earth well the

answer is simple it is due to inertia if you want to understand inertia i always connect it with the mother we know that every mother care about her children and she want to keep their children in good health similarly inertia always want to keep any body in its state of rest are in its state of uniform motion one can also say that inertia tends to keep the body and its initial position of rest our initial position of uniform motion for instance initially the paratrooper was moving in downward direction even the net force on the paratrooper

is zero but inertia tends to keep its uniform motion in downward direction remember that if a body is at rest the net force is always zero secondly if an object is in uniform motion the net force is again zero so in newton first law of motion we learned that there are two states of any object the first one is strata rest and the second one is state of uniform motion now here newton baba thought that what would happen if the net force on an object is not zero to answer this question newton baba presented his

second law of motion we know that if the ball is in the rest it is its natural state and the net force on the ball will always be equal to zero secondly if the car is in uniform motion it is also its natural state and the net force on the car will also be equal to zero now newton barber states that if we exert force on this stationary ball force will change its velocity for example initially the velocity of the ball was zero after exerting some sort of force on it let its velocity change to

5 meter per second we know that when velocity change acceleration produces so indirectly newton barbara states that when net force is not equal to zero it produces acceleration let me repeat it when net force is not equal to zero it produces acceleration secondly when we suddenly apply brake we exert force and the car comes to rest again newton baba states that force change velocity of the car for example let the initial velocity of the car was 30 meter per second after exerting some sort of force the velocity of the car is zero because it has

stopped here velocity is changed we know that when velocity change acceleration produces so indirectly newton baba states that when net force is not equal to zero it produces acceleration therefore acceleration is directly proportional to the applied force on a body he states that acceleration is inversely proportional to the mass of a body are we right f is equal to m a for example consider this car and this truck let the mass of this car is 100 kg and the mass of this truck is 200 kg let i exert 200 newton force on this car and

i also exert 200 newton force on this truck we would observe that the car will starts moving with acceleration of 2 meter per second square and the truck will start moving with acceleration of 1 meter per second squared here the truck is moving with acceleration of 1 meter per second squared because truck is 2 times heavier than the car so that's why we say that acceleration is inversely proportional to the mass of an object thus noted down all these important points of newton's second law now let me teach you the applications of newton's second law

of motion and daily life remember that every accelerated object is explained by newton's second law of motion for example when you kick a ball you exert force on it and the ball is accelerated in the direction of applied force secondly when we push accelerator of the car we exert more force on the car body as a result of this acceleration or speed of the car is increased just remember that every accelerated object is explained by the help of newton's second law of motion now what about the newton's third law of motion remember that newton's third

law of motion is all about physical interaction between two objects for example when you sit in a chair your body exerts a downward force on the chair let it is 600 newton at the same time the chair is also exerting an upward force of 600 newton on your body due to physical interaction between your body and the chair two forces are generated these two forces are called action and reaction forces therefore newton baba states that for every action there is an equal and opposite reaction for instance the magnitude of downward action and the magnitude of

upward reaction is the same which is 10 newton but remember that they both have the opposite direction thus remember this third law of action and reaction now let me teach you applications of newton's third law in our daily life consider a moving airplane we know that engine of the airplane forces the air in backward direction it is an action as a result of this action airplane will move in forward direction which is a reaction secondly when we walk on the ground our foot exert backward force on the ground which is an action as a result

of this the ground exerts equal force on our body in forward direction which is a reaction thirdly consider launching a rocket a rocket engine produces downward force which is called downward thrust as a result of this an upward force our upward thrust is produced which move the rocket an upward direction thus these are the different examples of newton's third law of motion in our daily life i hope that you have learned all about the laws of motion