Finding Angles of Interacting Forces

  • Thread starter Thread starter gajohnson
  • Start date Start date
  • Tags Tags
    Angles Forces
Click For Summary
SUMMARY

The discussion focuses on solving a physics problem involving the angles of interacting forces, specifically angles 67.4 and 22.6 degrees. The user attempted to apply the law of cosines to create a force triangle but encountered difficulties due to insufficient information to resolve three unknowns: the magnitudes of forces FBC and FBD, and the direction of FBD. The consensus is to assume a direction for FBD to proceed with calculations, as this will clarify the sense of the force and allow for a solution.

PREREQUISITES
  • Understanding of vector resolution in physics
  • Familiarity with the law of cosines
  • Basic knowledge of trigonometric functions
  • Ability to interpret force diagrams
NEXT STEPS
  • Study the law of cosines in the context of force triangles
  • Learn about vector resolution techniques in two dimensions
  • Practice problems involving angles of forces and equilibrium
  • Explore the concept of force direction and its implications in physics
USEFUL FOR

Students studying physics, particularly those focusing on mechanics and force interactions, as well as educators looking for examples of problem-solving in vector analysis.

gajohnson
Messages
70
Reaction score
0

Homework Statement



http://grab.by/lp4S

This probably shouldn't be too hard, but I'm getting pretty stuck. On the attached picture, the angles 67.4 and 22.6 are given, but I am not sure how they were found. Taking all the given information on the picture (besides those two angles), how would I find them? I think my trig is just rusty and there's probably an easy solution.


Homework Equations





The Attempt at a Solution



I tried to create a force triangle and use the law of cosines and to get F(BD), but that didn't work out, and I'm sort of stuck otherwise. Any help would be greatly appreciated. Thanks!
 
Physics news on Phys.org
From the picture, it seems you would have three unknowns: the magnitudes of forces FBC and FBD, and the direction of FBD. Resolving in two axes will only give you two equations, so there's not enough information to deduce the angle.
Where it says "since the direction of FBD is not clear", I think it only means the sense is unclear - i.e. is it positive or negative in the direction shown? For the purposes of solving the problem, just assume a particular sense and see what sign you get from the solution.
 

Similar threads

  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 7 ·
Replies
7
Views
3K
Replies
3
Views
1K
Replies
7
Views
3K
  • · Replies 3 ·
Replies
3
Views
2K
Replies
2
Views
1K
Replies
5
Views
2K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 15 ·
Replies
15
Views
4K