How can astronomers calculate the total mass ($M$) enclosed within a specific radius ($r$) using a known orbital velocity ($v$)?
Answer
By using the rearranged formula: $M = v^2 r / G$.
By rearranging Newton's law based on orbital dynamics, the total enclosed mass ($M$) can be calculated using the velocity ($v$) at a particular radius ($r$) and the gravitational constant ($G$).
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