---
title: "A U-tube with a uniform cross-section is open to the atmosphere and filled with water. A piston is placed in the left arm and pushed down with a constant force \\( F \\). If the right arm remains open, what is the difference in height \\( \\Delta h \\) between the water levels in the two arms?"
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url: "https://nerd-notes.com/ubq/107126/"
date_modified: "2026-08-18T02:38:26+00:00"
---

# A U-tube with a uniform cross-section is open to the atmosphere and filled with water. A piston is placed in the left arm and pushed down with a constant force \( F \). If the right arm remains open, what is the difference in height \( \Delta h \) between the water levels in the two arms?

A U-tube with a uniform cross-section is open to the atmosphere and filled with water. A piston is placed in the left arm and pushed down with a constant force \( F \). If the right arm remains open, what is the difference in height \( \Delta h \) between the water levels in the two arms?

- **A.** \( \Delta h = 0 \) (Water is incompressible)
- **B.** \( \Delta h = \frac{F}{\rho g A} \)
- **C.** \( \Delta h = \frac{2F}{\rho g A} \)
- **D.** \( \Delta h = \frac{F}{\rho g} \)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/107126/*