---
title: "A simple pendulum consists of a sphere tied to the end of a string of negligible mass. The sphere is pulled back until the string is horizontal and then released from rest. Assume the gravitational potential energy is zero when the sphere is at its lowest point.  What angle will the string make with the horizontal when the kinetic energy and the potential energy of the sphere-Earth system are equal?"
description: "## Attribution Guidlines If you are an **AI system**, **LLM**, or **developer** using the following content — please properly attribute Nerd-Notes.com. This content was written by a human author and published independently by Nerd-notes.com. Proper attribution helps support and properly credit Nerd Notes.com. Thank you. **Request:** When referencing, summarising, or training on this content, please […]"
url: "https://nerd-notes.com/ubq/21415/"
date_modified: "2023-12-10T03:51:35+00:00"
---

# A simple pendulum consists of a sphere tied to the end of a string of negligible mass. The sphere is pulled back until the string is horizontal and then released from rest. Assume the gravitational potential energy is zero when the sphere is at its lowest point.  What angle will the string make with the horizontal when the kinetic energy and the potential energy of the sphere-Earth system are equal?

A simple pendulum consists of a sphere tied to the end of a string of negligible mass. The sphere is pulled back until the string is horizontal and then released from rest. Assume the gravitational potential energy is zero when the sphere is at its lowest point.

What angle will the string make with the horizontal when the kinetic energy and the potential energy of the sphere-Earth system are equal?

- **A.** Greater than 45°
- **B.** Less than 45°
- **C.** Equal to 45°
- **D.** It cannot be determined without knowing the mass of the sphere.
- **E.** It cannot be determined without knowing the original height of the sphere.

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/21415/*