Parallel and perpendicular part of a vector

  • Thread starter cytochrome
  • Start date
  • #1
166
2

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

Answers and Replies

  • #2
SteamKing
Staff Emeritus
Science Advisor
Homework Helper
12,796
1,668
First, you might want to check the angle given by arctan (3/5).
 
  • #3
166
2
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?
 
  • #4
Doc Al
Mentor
45,029
1,325
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.
 
  • #5
166
2
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.
 

Related Threads on Parallel and perpendicular part of a vector

  • Last Post
Replies
3
Views
3K
Replies
1
Views
8K
Replies
5
Views
3K
Replies
2
Views
5K
Replies
10
Views
10K
  • Last Post
Replies
14
Views
34K
  • Last Post
Replies
11
Views
708
  • Last Post
Replies
1
Views
1K
  • Last Post
Replies
3
Views
5K
Replies
4
Views
13K
Top