---
title: "A block is attached to a cable and is being pulled up a frictionless incline at a constant speed. The system is defined to include the block and Earth. Which of the following statements correctly describes the total mechanical energy of the system as the block moves up the incline and provides a valid justification?"
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url: "https://nerd-notes.com/ubq/109207/"
date_modified: "2026-03-21T11:09:44+00:00"
---

# A block is attached to a cable and is being pulled up a frictionless incline at a constant speed. The system is defined to include the block and Earth. Which of the following statements correctly describes the total mechanical energy of the system as the block moves up the incline and provides a valid justification?

A block is attached to a cable and is being pulled up a frictionless incline at a constant speed. The system is defined to include the block and Earth. Which of the following statements correctly describes the total mechanical energy of the system as the block moves up the incline and provides a valid justification?

![A rectangular block on a ramp angled upward to the right. A cable attached to the right side of the block is parallel to the ramp and pulls the block upward. An arrow labeled v indicates the block moves at a constant velocity up the ramp.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-fig-1-1774091384-hoARcj.jpg)

- **A.** The mechanical energy increases because the cable exerts an external force that performs positive work on the system.
- **B.** The mechanical energy decreases because the gravitational force performs negative work on the block as it rises.
- **C.** The mechanical energy stays the same because the block moves at a constant speed, so its kinetic energy does not change.
- **D.** The mechanical energy stays the same because the positive work performed by the cable is exactly canceled by the negative work performed by gravity.

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/109207/*