Parallel and perpendicular part of a vector

Click For Summary

Homework Help Overview

The discussion revolves around resolving a force vector into its components, specifically a part that is perpendicular to one line segment (AB) and a part that is parallel to another line segment (BC). The context involves vector analysis and trigonometric relationships.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the setup of the problem and the correctness of the initial diagram. There are questions about the use of trigonometric functions to find the components of the force vector, specifically whether F*cos(θ) and F*sin(θ) are the correct methods for determining parallel and perpendicular components, respectively.

Discussion Status

The discussion is ongoing, with participants providing feedback on the initial setup and questioning the accuracy of the diagram and the provided answers. Some guidance has been offered regarding the angle calculation, but there is no explicit consensus on the correctness of the methodology or the initial conditions.

Contextual Notes

There is mention of potential inaccuracies in the solutions provided in an old textbook, which may affect the discussion. Participants are also considering whether the initial diagram accurately represents the problem setup.

cytochrome
Messages
163
Reaction score
3

Homework Statement


Resolve the force F into

a) a part perpendicular to AB and

b) a part parallel to BC


Homework Equations


a dot b = ab*cos(θ)


The Attempt at a Solution


I attached my attempt in the .pdf file. For some reason it is wrong. I don't understand how my reasoning is incorrect.

The orange square in the picture is a supposed to be a wooden box in the problem, so that detail is not important to the problem.
 

Attachments

Physics news on Phys.org
First, you might want to check the angle given by arctan (3/5).
 
SteamKing said:
First, you might want to check the angle given by arctan (3/5).

Thanks for pointing that out, but the answer still comes out to be wrong even if I change that. Am I setting up the problem wrong?

Do you do F*cos(θ) to find a parallel component of F and F*sin(θ) to find a perpendicular part of F in general?
 
cytochrome said:
Thanks for pointing that out, but the answer still comes out to be wrong even if I change that. Am I setting up the problem wrong?
Are you sure that your initial diagram is correct? The given answers do not seem to match the diagram.

Do you do F*cos(θ) to find a parallel component of F and F*sin(θ) to find a perpendicular part of F in general?
Yes.
 
Doc Al said:
Are you sure that your initial diagram is correct? The given answers do not seem to match the diagram.


Yes.

Yes my diagram is correct. It's possible the solutions could be wrong, it's out of an old book... Anyways, I was wondering if my methodology was correct.
 

Similar threads

Replies
26
Views
2K
Replies
24
Views
2K
  • · Replies 1 ·
Replies
1
Views
9K
  • · Replies 2 ·
Replies
2
Views
7K
  • · Replies 15 ·
Replies
15
Views
1K
Replies
11
Views
3K
  • · Replies 20 ·
Replies
20
Views
4K
  • · Replies 3 ·
Replies
3
Views
2K
Replies
3
Views
4K
  • · Replies 5 ·
Replies
5
Views
4K