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Fixes #37 .

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Thanks for clarifying! I have a suggestion that sounds not natural to me, what do you think?

where $\ddot{\vector{R}}$ is the **absolute acceleration** of the subscripted mass. Absolute means that the acceleration is taken relative to an inertial reference frame. This is important because Newton's second law only applies for absolute accelerations.

Since the only force in this system is the gravitational attraction, the force is also equal to Newton's law of gravitation, {eq}`eq:newtons-law-of-gravitation`. The force of $m_2$ on $m_1$, $F_{12}$, points in the _positive_ direction of $\uvec{u}_r$. Because of Newton's third law, as represented by {eq}`eq:newtons-third-law-for-two-body`, the force of $m_1$ on $m_2$, $F_{21}$, points in the negative direction of $\uvec{u}_r$. This is shown in {eq}`eq:gravitational-force-two-body`:
Since the only force in this system is the gravitational attraction, the force may also be described by Newton's law of gravitation, {eq}`eq:newtons-law-of-gravitation`. The force of $m_2$ on $m_1$, $F_{12}$, points in the _positive_ direction of $\uvec{u}_r$. Because of Newton's third law, as represented by {eq}`eq:newtons-third-law-for-two-body`, the force of $m_1$ on $m_2$, $F_{21}$, points in the negative direction of $\uvec{u}_r$. This is shown in {eq}`eq:gravitational-force-two-body`:
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I think I prefer "the force may be computed by Newton's..."

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Sounds good! Changed.

@NattyBumppo NattyBumppo requested a review from bryanwweber May 30, 2025 00:55
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Thank you!

@bryanwweber bryanwweber enabled auto-merge (squash) May 30, 2025 03:09
@bryanwweber bryanwweber merged commit 51fe79e into bryanwweber:main May 30, 2025
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@NattyBumppo NattyBumppo deleted the two_body_wording_change branch May 30, 2025 03:13
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Sentence describing force in two-body systems is poorly worded

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