Solving Plane Pressure Problem: Finding the Line of Action

Click For Summary

Homework Help Overview

The discussion revolves around understanding the derivation of an equation related to pressure on a plane, specifically equation 15.16, as presented in a textbook. The original poster is preparing for an exam and seeks clarification on the methodology used to arrive at this equation, particularly regarding the concept of the line of action and its relation to moments.

Discussion Character

  • Exploratory, Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants discuss the potential methods for deriving the equation, including the use of centroids and integration of pressure as a function of depth. Questions are raised about the clarity and completeness of the information provided in the textbook.

Discussion Status

There is an ongoing exploration of different interpretations regarding the derivation of the equation. Some participants express skepticism about the completeness of the textbook's explanation, while others suggest that the centroid may have been used as a straightforward approach. Clarifications are sought regarding the formulation of the equations mentioned.

Contextual Notes

One participant notes that the equation in question is illegible, which may hinder the discussion. The original poster is also under the constraints of preparing for an exam, which adds urgency to their inquiry.

Phys5
Messages
1
Reaction score
0

Homework Statement


I am trying to study for an exam and a section in the book on pressure on a plane is shown in the attached picture. I am trying to understand how equation15.16 was derived. I know normally the line of action is found using moments so this seems to be a short cut but I can'tunderstand how the book got to this equation. Any help would be muchappreciated. Thanks![/B]

Homework Equations

The Attempt at a Solution

 

Attachments

  • IMG_0181.JPG
    IMG_0181.JPG
    39.8 KB · Views: 424
Physics news on Phys.org
Equation 15.16 is illegible. Please post it with a better picture. Also post the relevant equations and your bet attempt at solving or understanding what is going on.
 
I don't believe the issue is that they took some clever shortcut as it is that they plain just didn't say anything about how they got there. I am sure they just found the centroid as the that is pretty easy and I can't imagine there being anything shorter.

Write the pressure as a function of depth h and integrate

∫ h P(h) / ∫ P(h)

from h1 to h2.
 
Cutter Ketch said:
∫ h P(h) / ∫ P(h)
This is not an equation. An equation has two sides. Which side is this, what is the other side and what is the equation supoosed to represent?
 
Cutter Ketch said:
I am sure they just found the centroid
Or even just looked it up... Centroid of a trapezoid.
 

Similar threads

A water-bottle demonstration of atmospheric pressure
  • · Replies 6 ·
Replies
6
Views
2K
Calculating flux through a plane cutting two concentric cylinders
  • · Replies 26 ·
Replies
26
Views
2K
Pressure in a gas container measured with a barometer and a U pipe
  • · Replies 6 ·
Replies
6
Views
2K
Equation for Fourth Force and its Line of Action?
  • · Replies 6 ·
Replies
6
Views
1K
Solving Fluid Statics Problem: Accounting for Atmospheric Pressure
  • · Replies 9 ·
Replies
9
Views
2K
Pressure reported from a water line, gauge or absolute?
  • · Replies 5 ·
Replies
5
Views
2K
Magnetic field pointing into a normal magnetized compass needle
  • · Replies 16 ·
Replies
16
Views
2K
Question Concerning The Coefficient of Friction: Block on a Rough Inclined Plane
  • · Replies 5 ·
Replies
5
Views
2K
Find Isobaric Expansion & Pressure-Volume Coefficient for Solid
  • · Replies 4 ·
Replies
4
Views
2K
Dynamics problem involving an inclined plane and Friction
  • · Replies 1 ·
Replies
1
Views
2K