---
title: "A scientific probe of mass \\(m\\) travels in a stable circular orbit of radius \\(r\\) around a planet of mass \\(M\\), where \\(M \\gg m\\). The gravitational potential energy of the probe-planet system is defined to be zero at infinite separation. Which of the following expressions represents the total mechanical energy of the probe-planet system?"
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url: "https://nerd-notes.com/ubq/120876/"
date_modified: "2026-08-23T04:44:00+00:00"
---

# A scientific probe of mass \(m\) travels in a stable circular orbit of radius \(r\) around a planet of mass \(M\), where \(M \gg m\). The gravitational potential energy of the probe-planet system is defined to be zero at infinite separation. Which of the following expressions represents the total mechanical energy of the probe-planet system?

A scientific probe of mass \(m\) travels in a stable circular orbit of radius \(r\) around a planet of mass \(M\), where \(M \gg m\). The gravitational potential energy of the probe-planet system is defined to be zero at infinite separation. Which of the following expressions represents the total mechanical energy of the probe-planet system?

- **A.** \(-\dfrac{GMm}{r}\)
- **B.** \(-\dfrac{GMm}{2r}\)
- **C.** \(+\dfrac{GMm}{2r}\)
- **D.** \(+\dfrac{GMm}{r}\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/120876/*