---
title: "An astronaut of mass \\(m\\) is inside a space station that is in a stable circular orbit around Earth at an altitude \\(h\\). Earth has mass \\(M\\) and radius \\(R\\). Which of the following best explains why the astronaut feels weightless while in orbit?"
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url: "https://nerd-notes.com/ubq/109932/"
date_modified: "2026-03-26T06:56:52+00:00"
---

# An astronaut of mass \(m\) is inside a space station that is in a stable circular orbit around Earth at an altitude \(h\). Earth has mass \(M\) and radius \(R\). Which of the following best explains why the astronaut feels weightless while in orbit?

An astronaut of mass \(m\) is inside a space station that is in a stable circular orbit around Earth at an altitude \(h\). Earth has mass \(M\) and radius \(R\). Which of the following best explains why the astronaut feels weightless while in orbit?

![The diagram shows Earth as a large, solid blue circle in the center. A light-gray dashed line forms a perfect circle concentric with Earth, representing the orbital path of a space station. A small, white rectangular box represents the space station, located at the 3 o'clock position on the orbital path. Inside the space station, a small black dot represents an astronaut. A single red vector arrow originates from the black dot and points horizontally to the left, directly toward the center of Earth. This arrow is labeled with the symbol \(F_g\). There are no other force vectors shown on the astronaut.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-fig-1-1774508212-5ogMIO.jpg)

- **A.** The astronaut feels weightless because the gravitational force exerted by Earth is zero at the altitude of the space station.
- **B.** The astronaut feels weightless because the astronaut and the station are both in freefall, accelerating toward Earth at the same rate.
- **C.** The astronaut feels weightless because the gravitational field strength of Earth is negligible at the distance of the orbit.
- **D.** The astronaut feels weightless because the circular motion of the station creates an outward centrifugal force that cancels the inward gravitational force.

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/109932/*