13.1: The Law of Gravitation
- Page ID
- 32820
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Of Newton’s accomplishments, the discovery of the universal law of gravitation ranks as one of the greatest. Imagine two masses, \(M_{1}\) and \(M_{2}\), separated by a distance \(r\). The force has the magnitude
\[F=\frac{M_{1} M_{2} G}{r^{2}}\label{13.1}\]
where \(G=6.67 \times 10^{-11} \mathrm{~m}^{3} \mathrm{~kg}^{-1} \mathrm{~s}^{-2}\) is the universal gravitational constant. The gravitational force is always attractive and it acts along the line of centers between the two masses