Though everyone learned Newton’s Third Law in elementary school level, I had seen many of the people doing this mistake while understanding it. I am not an exception at my school level.
The mistake is this,
If I ask a school student to identify all the action and reaction pairs in the photo of an apple that is on a table,
The student will immediately give the answer as only one pair and that is ,
Action: Earth pulls apple with the Gravitational force acting downwards direction [direction towards the earth].
Reaction: Table pushes apple with the Normal reaction acting upwards that is opposite to the direction towards the earth.
The student forgets to realize the fact, since his mind is fully concentrated only on the word Opposite.
But here is what you have to note or surprise about the ingeniousness of Newton. He didn’t had done the mistake as same as the student did.
Before proposing the Third law, Newton cleverly thought about another experiment that is a falling apple towards the earth. It is the perfect example where one can really understand the Newton’s Third Law.
While considering the case of a falling apple and trying to identify the action and the reaction pairs,
Some of the photos of falling apple are as follows,
From his gravitational law, he was known that some force of attraction is there between an apple and the Earth.
Mostly in our first thought we will only realize the Action,
Action: Earth pulls Apple with gravitational force acting downwards that is to the Centre of Mass of the Earth.
But the amazing fact lies there in its pair,
From the relative frame of reference and from the gravitational law, it should be there the reaction as,
Reaction: Apple pulls Earth with same gravitational force acting upward toward the Centre of mass of Apple.
Note: It needn’t be earth pulls apple should be action or Apple pulls Earth should be action. Either one of the force can be action or reaction since action, reaction happens simultaneously.
Note: Both these force pairs are same in magnitude. The forces are same but not the acceleration. Acceleration of Earth is so minute and the acceleration of Apple is so high that is 9.8 m/s^2 near to the ground.
On hearing this first time, I take time to believe this fact in my childhood. I thought, How can this small apple pull The Whole Earth upwards? It looked crazy to me.
But then I realized the fact. Since the Mass of the Earth is too large the acceleration of the Earth is so minute so that it couldn’t be seen with our eyes. Nevertheless it is a wonderful and amazing fact that everyone should know.
These kind of mistakes are often in our everyday lives. Thank God for the sake of Newton never did the Same mistake.
The real action, reaction pairs are explained by Newton as follows,
For every force there is an equivalent and opposite force acting on the opposite direction of the force. You cannot say which force is action and which is reaction. Action and reaction happens at same time. The forces are same in magnitude and Opposite in direction.
Moreover everyone need to note this special point that is,
Note: The action and reaction pair should always be the Same Kind of Force.
That is for an action of gravitational force the reaction force cannot be the Normal force or any other force. It should be also the same Gravitational force.
And that is the note where most of the Students are getting wrong. Do this mistake as I did in your school age because when you did find the real answer you will be amazed like me.
Why I am explaining this mistake is because it is the first thing that made me very much interested in Physics. From this, I started to see the Physics as a Magical one that explains all the Magic in this great enormous Universe.
Answer to the first question (If you need):
The real Action – Reaction pairs in the case of an apple on the table is,
There are four pairs,
First pair:
* Earth pulls Table with gravitational force towards its centre of mass
** Table pulls Earth with gravitational force towards its centre of mass
Fourth Pair
* Table pushes Earth with Normal Reaction acting downwards
** Earth pushes Table with Normal Reaction acting upwards
Always keep in mind that Newton’s Third Law is just the matter of the Relative phenomenon of a force between two bodies.
The mistake is this,
If I ask a school student to identify all the action and reaction pairs in the photo of an apple that is on a table,
The student will immediately give the answer as only one pair and that is ,
Action: Earth pulls apple with the Gravitational force acting downwards direction [direction towards the earth].
Reaction: Table pushes apple with the Normal reaction acting upwards that is opposite to the direction towards the earth.
The student forgets to realize the fact, since his mind is fully concentrated only on the word Opposite.
But here is what you have to note or surprise about the ingeniousness of Newton. He didn’t had done the mistake as same as the student did.
Before proposing the Third law, Newton cleverly thought about another experiment that is a falling apple towards the earth. It is the perfect example where one can really understand the Newton’s Third Law.
While considering the case of a falling apple and trying to identify the action and the reaction pairs,
Some of the photos of falling apple are as follows,
Mostly in our first thought we will only realize the Action,
Action: Earth pulls Apple with gravitational force acting downwards that is to the Centre of Mass of the Earth.
But the amazing fact lies there in its pair,
From the relative frame of reference and from the gravitational law, it should be there the reaction as,
Reaction: Apple pulls Earth with same gravitational force acting upward toward the Centre of mass of Apple.
Note: It needn’t be earth pulls apple should be action or Apple pulls Earth should be action. Either one of the force can be action or reaction since action, reaction happens simultaneously.
Note: Both these force pairs are same in magnitude. The forces are same but not the acceleration. Acceleration of Earth is so minute and the acceleration of Apple is so high that is 9.8 m/s^2 near to the ground.
On hearing this first time, I take time to believe this fact in my childhood. I thought, How can this small apple pull The Whole Earth upwards? It looked crazy to me.
But then I realized the fact. Since the Mass of the Earth is too large the acceleration of the Earth is so minute so that it couldn’t be seen with our eyes. Nevertheless it is a wonderful and amazing fact that everyone should know.
These kind of mistakes are often in our everyday lives. Thank God for the sake of Newton never did the Same mistake.
The real action, reaction pairs are explained by Newton as follows,
For every force there is an equivalent and opposite force acting on the opposite direction of the force. You cannot say which force is action and which is reaction. Action and reaction happens at same time. The forces are same in magnitude and Opposite in direction.
Moreover everyone need to note this special point that is,
Note: The action and reaction pair should always be the Same Kind of Force.
That is for an action of gravitational force the reaction force cannot be the Normal force or any other force. It should be also the same Gravitational force.
And that is the note where most of the Students are getting wrong. Do this mistake as I did in your school age because when you did find the real answer you will be amazed like me.
Why I am explaining this mistake is because it is the first thing that made me very much interested in Physics. From this, I started to see the Physics as a Magical one that explains all the Magic in this great enormous Universe.
Answer to the first question (If you need):
The real Action – Reaction pairs in the case of an apple on the table is,
There are four pairs,
First pair:
* Apple pulls Earth with gravitational force acting upwards that is towards the Centre of mass of Apple.
**Earth pulls Apple with gravitational force acting downwards that is towards the Centre of Mass of the Earth.Second Pair:
* Table pushes apple with the Normal reaction acting upwards.Third Pair:
** Apple pushes Table with the Normal reaction acting downward.
* Earth pulls Table with gravitational force towards its centre of mass
** Table pulls Earth with gravitational force towards its centre of mass
Fourth Pair
* Table pushes Earth with Normal Reaction acting downwards
** Earth pushes Table with Normal Reaction acting upwards
Always keep in mind that Newton’s Third Law is just the matter of the Relative phenomenon of a force between two bodies.
No comments:
Post a Comment
Let everyone know what you think about this