Newton’s Universal Law of Gravitation

Level: Class 9, CBSE, Physics, Gravitation

• Universal law of gravitation by Newton
• Let us consider two masses, m1 and m2.
• The distance between the centres of the two masses is r.
• Force, F is directly proportional to mass 1 and mass 2.
• F is inversely proportional to the square of the distance between the two masses.
• Let us combine these two relations.
• To remove the proportionality, we have to introduce a constant.
• The proportionality constant is G.
• G = Gravitational Constant
• We can derive the unit of Gravitational constant as shown here.
• The value of Gravitational Constant, G = 6.67 x 10^-11 Nm²kg^-2