Physics – Universal Law of Gravitation – Part 1


We saw that the gravitational force is the attractive force between any two objects with non-zero mass seperated by a distance. So does the Apple fall towards the Earth or does the Earth move towards the Apple? Or do both move towards each other? It’s actually simple logic! This is the Earth, and say this minuscule object is an Apple. Based on what we learnt about the gravitational force, both apply an equal force to attract the other object towards itself. So if the forces are equal which one will accelerate more? Based on the Newton’s second law, we know that the force applied is the product of mass and acceleration. So the acceleration will equal ‘Force over the mass’. The acceleration is inversely proportional to the mass. If the mass is more, the acceleration will be lesser. As the mass of the Earth is MUCH MUCH MUCH more than the mass of the Apple, It is the Apple that accelerates towards the Earth and not the other way around. Hope that makes it clear. Now the question is ‘how do we quantify this force?’ To understand this, we need to understand a simple concept! And this simple concept is called the Universal law of Gravitation. Say there are two objects A and B separated by a distance ‘d’. The distance between the centres is considered the distance between the 2 objects and not this distance. Assume that the mass of object A is ‘m1’ and that of object B is ‘m2’. As object A is bigger, let’s assume ‘m1’ to be bigger than ‘m2’. The Universal law of gravitation says that, ‘Every object in the universe attracts every object with a force which is DIRECTLY proportional to the product of their masses and INVERSELY proportional to the SQUARE of the distance between them’. Let me repeat. The force is Directly proportional to the PRODUCT of their masses and INVERSELY proportional to the SQUARE of the distance between them. With this data, we can write it mathematically like this. So if the mass of any of the objects increases, the gravitational force will have more magnitude. And more the distance between the two objects, the lesser will the gravitational force! Directly proportional to the product of the masses, and inversely proportional to the square of the distance between them. This can be written as F equals G times m1 one times m2 over ‘d’ squared. ‘G’ here is the Constant of proportionality and is called the UNIVERSAL GRAVITAITONAL CONSTANT. The equation can be modified and written as G equals ‘F times d squared’ over ‘m1 times m2’. The value of ‘G’ was found out by Lord Henry Cavendish using a Torsion Balance. The universally accepted value of G is ‘six point six seven three’ times ‘ten raised to negative 11’. What will be the units of G? Force is Newtons. As the distance is in meters, we have ‘meters squared’. And as the mass is measured using kilograms, we multiply this with ‘kilograms raised to negative 2’. This is the value of the Universal gravitational constant!

100 comments

  1. In future don't memorise would be the most trending educational site ……bst wishes
    btw gr8 explanation
    helped me a lot ……ty don't memorise ::))

  2. isn't Newton's "law" a theory, when did his theory of gravity, like Einstein's theory of gravity and relativity, become fact-law?

  3. mam…ur videos is awesome….so clear and best channel for mee yet now…but there is problem there is no topics according to cbse….like i see ur all videos but no found the gravitation constant topic…no sequence wise

  4. No word for this video because this video is amazing, superb, fantastic, mind-blowing. 💕💕💕💕💕💕💕💕💕💕💕💕💕💕💕💕💕💕💕💕💕💕💕💕💕💕💕💕💕💕💕💕💕💕💕💕💕

  5. O my GOD! It's just fantabulous 👏…. I have understood this topic very easily…. thank you very much for this vedio
    ….. keep making these vedios …..
    .

  6. No object is put on
    motion without the hit of an external force. Since there should be an
    initially force applied to an object in order for the object to start
    it state of motion, therefore there is acceleration involved for any
    object in motion. As long as the acceleration is not zero the object
    velocity should increase and increase to infinity, assuming the
    object is not under the influence of any external forces at all.

    Example, suppose an

    object is suspended without any, whatsoever, forces acting on it.
    Now, you hit the object with something. So the object will start its
    motion. This means the object will begin with acceleration. Does
    this positive acceleration remains with the object. Again assuming
    the object not being subjected to any external forces. If the object
    is under the influence of acceleration due to the initial hitting
    then the velocity of the object will keep increasing and increasing.
    So an object in motion will not continue its journey with constant
    velocity. That is an object in heaven in motion must be under a
    positive acceleration and with a non zero acceleration the velocity
    keep increasing. Would you please clear me about this subject? Thank
    you

  7. This is the best explanation video I have seen so far, really thank you for the simple clarifications. It made me understand the concept very quickly and easily, I hope you will continue doing this way. Keep it up and I’m sure you will be successful in the future (hopefully). 😄❤️👍

  8. Mass as such does nothing. Neither attract nor repulses. Think about it. Why should this be so? It’s nonsense.

  9. This "universal law" tells us, that gravitational force between Sun and Moon is greater than force between Earth and Moon, but Moon is still Earth's satellite…

  10. Very very great videos, very easy to understand, short and sweet, thanks a lot for animation video creation.

    Keep it up. God bless you.

  11. Mam i have only one question, that is why we take square of the distance??
    I am not understanding, please help me mam.

    Mam are you Indian.

  12. Moscow Aviation Institute – MAI – International Student's Page has given the following the thumbs up. It's all clearly correct.

    The Institute of Physics, Patna has now given the following writing the thumbs up. Excellent.♥️

    THE MATHEMATICAL PROOF THAT ELECTROMAGNETISM/ENERGY IS GRAVITY IN A BALANCED FASHION IS SUCCESSFULLY DEMONSTRATED:

    "Mass"/ENERGY IS GRAVITY. ELECTROMAGNETISM/ENERGY IS GRAVITY. THE SUN AND THE EARTH are F=ma AND E=mc2, AS ELECTROMAGNETISM/ENERGY IS GRAVITY. E=mc2 is DIRECTLY AND FUNDAMENTALLY DERIVED FROM F=ma. F=ma AND E=mc2 PROVE that ELECTROMAGNETISM/ENERGY IS GRAVITY, AS ALL of SPACE is NECESSARILY ELECTROMAGNETIC/GRAVITATIONAL (IN BALANCE); AS ELECTROMAGNETISM/ENERGY IS GRAVITY. "Mass"/ENERGY IS GRAVITY. ELECTROMAGNETISM/ENERGY IS GRAVITY. Energy has/involves GRAVITY, AND ENERGY has/involves inertia/INERTIAL RESISTANCE. Gravity/acceleration involves BALANCED inertia/INERTIAL RESISTANCE, AS ELECTROMAGNETISM/ENERGY IS GRAVITY. This explains F=ma AND E=mc2, AS ELECTROMAGNETISM/ENERGY IS GRAVITY. SO, GRAVITATIONAL FORCE/ENERGY IS proportional to (or BALANCED with/as) inertia/INERTIAL RESISTANCE; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. ACCORDINGLY, ALL of SPACE is NECESSARILY ELECTROMAGNETIC/GRAVITATIONAL (IN BALANCE); AS ELECTROMAGNETISM/ENERGY IS GRAVITY. "Mass"/ENERGY involves BALANCED inertia/INERTIAL RESISTANCE consistent WITH/AS what is BALANCED ELECTROMAGNETIC/GRAVITATIONAL FORCE/ENERGY, AS ELECTROMAGNETISM/ENERGY IS GRAVITY. GREAT !!! Gravity IS ELECTROMAGNETISM/ENERGY. ELECTROMAGNETISM/ENERGY IS GRAVITY. INDEED, A PHOTON may be placed at the center of THE SUN (as A POINT, of course); as the reduction of SPACE is offset by (or BALANCED with) the SPEED OF LIGHT; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. GREAT. "Mass"/ENERGY IS GRAVITY. ELECTROMAGNETISM/ENERGY IS GRAVITY. ALL of SPACE is NECESSARILY ELECTROMAGNETIC/GRAVITATIONAL (IN BALANCE), AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Great. The ability of thought to DESCRIBE OR RECONFIGURE sensory experience is ULTIMATELY dependent upon the extent to which THOUGHT IS SIMILAR TO sensory experience. (THOUGHTS ARE INVISIBLE.) Gravity IS ELECTROMAGNETISM/ENERGY. ELECTROMAGNETISM/ENERGY IS GRAVITY.

    Very importantly, outer "space" involves full inertia; AND it is FULLY INVISIBLE AND black. The perpetual motion of WHAT IS THE EARTH is NOW explained. GREAT !!! The idea that THE PLANETS are "falling" in what is "curved space" in RELATION to what is THE SUN is PROVEN to be NONSENSE. So, the falling objects must be considered in RELATION to WHAT IS THEN THE ORBITING EARTH. GREAT !!!!!!!!!!

    By Frank DiMeglio

  13. Moscow Aviation Institute – MAI – International Student's Page has given the following the thumbs up. It's all clearly correct.

    The Institute of Physics, Patna has now given the following writing the thumbs up. Excellent.♥️

    THE MATHEMATICAL PROOF THAT ELECTROMAGNETISM/ENERGY IS GRAVITY IN A BALANCED FASHION IS SUCCESSFULLY DEMONSTRATED:

    "Mass"/ENERGY IS GRAVITY. ELECTROMAGNETISM/ENERGY IS GRAVITY. THE SUN AND THE EARTH are F=ma AND E=mc2, AS ELECTROMAGNETISM/ENERGY IS GRAVITY. E=mc2 is DIRECTLY AND FUNDAMENTALLY DERIVED FROM F=ma. F=ma AND E=mc2 PROVE that ELECTROMAGNETISM/ENERGY IS GRAVITY, AS ALL of SPACE is NECESSARILY ELECTROMAGNETIC/GRAVITATIONAL (IN BALANCE); AS ELECTROMAGNETISM/ENERGY IS GRAVITY. "Mass"/ENERGY IS GRAVITY. ELECTROMAGNETISM/ENERGY IS GRAVITY. Energy has/involves GRAVITY, AND ENERGY has/involves inertia/INERTIAL RESISTANCE. Gravity/acceleration involves BALANCED inertia/INERTIAL RESISTANCE, AS ELECTROMAGNETISM/ENERGY IS GRAVITY. This explains F=ma AND E=mc2, AS ELECTROMAGNETISM/ENERGY IS GRAVITY. SO, GRAVITATIONAL FORCE/ENERGY IS proportional to (or BALANCED with/as) inertia/INERTIAL RESISTANCE; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. ACCORDINGLY, ALL of SPACE is NECESSARILY ELECTROMAGNETIC/GRAVITATIONAL (IN BALANCE); AS ELECTROMAGNETISM/ENERGY IS GRAVITY. "Mass"/ENERGY involves BALANCED inertia/INERTIAL RESISTANCE consistent WITH/AS what is BALANCED ELECTROMAGNETIC/GRAVITATIONAL FORCE/ENERGY, AS ELECTROMAGNETISM/ENERGY IS GRAVITY. GREAT !!! Gravity IS ELECTROMAGNETISM/ENERGY. ELECTROMAGNETISM/ENERGY IS GRAVITY. INDEED, A PHOTON may be placed at the center of THE SUN (as A POINT, of course); as the reduction of SPACE is offset by (or BALANCED with) the SPEED OF LIGHT; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. GREAT. "Mass"/ENERGY IS GRAVITY. ELECTROMAGNETISM/ENERGY IS GRAVITY. ALL of SPACE is NECESSARILY ELECTROMAGNETIC/GRAVITATIONAL (IN BALANCE), AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Great. The ability of thought to DESCRIBE OR RECONFIGURE sensory experience is ULTIMATELY dependent upon the extent to which THOUGHT IS SIMILAR TO sensory experience. (THOUGHTS ARE INVISIBLE.) Gravity IS ELECTROMAGNETISM/ENERGY. ELECTROMAGNETISM/ENERGY IS GRAVITY.

    Very importantly, outer "space" involves full inertia; AND it is FULLY INVISIBLE AND black. The perpetual motion of WHAT IS THE EARTH is NOW explained. GREAT !!! The idea that THE PLANETS are "falling" in what is "curved space" in RELATION to what is THE SUN is PROVEN to be NONSENSE. So, the falling objects must be considered in RELATION to WHAT IS THEN THE ORBITING EARTH. GREAT !!!!!!!!!!

    By Frank DiMeglio

  14. Where can we see this phenomenon of mass attracting mass here on Earth perhaps near a big mountain?
    To quote the Cavendish experiment is an embarrassment, have you researched it?

    It was set in a room in or adjoining his house – the device was not his design it was passed to him and he carried out a few
    modifications. It was primarily made of wood which as you know over time will suffer shrinkage and warping (He confirmed that moisture had ingress-ed some components).

    Whilst continuing to take his readings he did the following; He subjected the balls to a flame to see what effect heat would have He subjected
    the balls to magnets to see what effect magnetism would have.

    He drilled holes in the balls to insert a thermometer He asked his butler / friend to carry on with the measurements when he went off for a few days.

    There was no temperature control in the room (This is most critical)

    His calculations have been found to be incorrect (Proven by Hutton).

    After each one of these he should have re calibrated and started from scratch – he did not.

    He also admitted the balls were not hung centrally on their axis but thought the impact was negligible.
    Any one of the above would render any science experiment void yet we are supposed to believe a constant was achieved. Boys did a similar experiment far more scientific by a long shot than Cavendish but obtained contradictory results.

    Hutton and Maskelyne determined their pendulum mountain experiments were far more accurate than cavendish.

    Airy tried to find the mean density of the earth up and down a mine shaft but met with contradictory results also.

    Transactions of the Royal Society 1847, Sir JFW Herschel On the Cause of the Discrepancies observed by Mr Baily with the Cavendish apparatus for determining the Mean density of the Earth he states; I must not here be understood as insinuating any kind of deception on the part of the great experimental philosopher, on the contrary he is candid in the extreme. He frequently refers to the 'variation in the time of vibration and perturbation of the resting points' as things for which he cannot account, and sometimes says 'there must be some disturbing
    force'. also the force of torsion must be subject to variation'.

    Herschel is also critical of the magnetising of the balls stating that despite being mainly lead they will retain some magnetic properties for a period of time.

    The mean density of the Earth has never and will never be known therefore all calculations based on it are null and void. Look at these experts in their field try to embarrassingly explain gravity. https://www.youtube.com/watch?v=7lui9qZ6cDs&t=851s

    All of the above are extracts from Cavendish himself and from Royal Society papers.

  15. चेतावनी – गुरुत्वाकर्षण का अस्तित्व है ही नहीं । ये एक "अवैज्ञानिक कल्पना" है, जिसके कारण ही विज्ञान गलत दिशा में जा रहा है और आज भी ब्रह्माण्ड हमारे लिए एक, अनुत्तरित प्रश्न बना हुआ है I 

    यदि आप मानते हैं कि, वास्तव में गुरुत्वाकर्षण का अस्तित्व है तो, गुरुत्वाकर्षण बल की दिशा को, तीर के माध्यम से दर्शाने का प्रयास करे । जिस प्रकार, ब्रह्मांड में लगने वाले प्रत्येक बल की दिशा को, सरलता से, तीर द्वारा प्रदर्शित करना संभव है । मेरी आपको चुनौती है, आप नहीं दर्शा पाएंगे, क्योंकि वास्तव में गुरुत्वाकर्षण का कोई अस्तित्व है ही नहीं ।  

    लेकिन, वो कौन सा बल है, जो गुरुत्वाकर्षण के स्थान पर, वास्तव में कार्य कर रहा है? इसकि ठोस जानकारी के लिए, क्लिक करें – https://youtu.be/q_Zqr0cUcI8

  16. Mam I am watching your videos since last two years and these prove very helpful for me but mam I request you to clear my doubt regarding how planets revolve around sun? Man please clear my this doubt. I will be thankful to you If you clear my doubt

  17. Who else just wants to kill that apple sh*t 🍎 ? Only me? ok then…… because it all started with that apple who just couldn't stay on that tree…..😡

  18. I never thought that Physics could be explained in such a simple manner yet effectively. Thank You, Don't Memorise 🙂

  19. For me, Newton's gravity laws are NOT correct, even according to Newton …

    In fact if we have A(M) and B(m) and M > m, so F(A/B) = G'(M + m)m/AB² and F(B/A) = 0 (G' is a little bit smaller than G = 6.67 x 10⁻¹¹ isu)

    My question is : what happens if we have M = m ? (the answer is very logic …)

    To serve you. professeur essef, in mathematics (active for a year on Youtube & Wikipédia, in astronomy & astrophysics). 2019 December 5

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