Finding the Magnitude of a Vertical Force in a Simple 3D Statics Problem

  • Thread starter Thread starter Ortix
  • Start date Start date
  • Tags Tags
    3d Statics
AI Thread Summary
To determine the magnitude of the vertical force F in the 3D statics problem, the tension in cable AB is given as 700N. The approach involves breaking down the tension into its x, y, and z components, leading to three equations with three unknowns: F, AC, and AD. While the original poster feels overwhelmed by the calculations, it's emphasized that using unit vectors (i, j, k) simplifies the process, especially when angles are not provided. The key is to treat the total tension as 700N rather than its components. Overall, the solution requires careful component analysis and application of static equilibrium principles.
Ortix
Messages
63
Reaction score
0

Homework Statement


If cable AB is subjected to a tension of 700N determine the magnitude of the vertical force F in N.

Pic:
[PLAIN]http://img225.imageshack.us/img225/9823/capturespm.png


Homework Equations


Sum of forces in x y and z direction


The Attempt at a Solution


I am retaking my statics course after i switched majors (long story) and i kind of forgot how to solve this the RIGHT way.

My approach would be first breaking up all the tensions in the x y and z components and summing all of those. I'll end up with 3 equations and 3 unknowns (F, AC and AD). I just feel like that's too much work...

On top of that my book makes use of i j and k but in those problems angles are given (which does make it easier to calculate the components)

Could someone give me a quick rundown on how to solve this?
 
Last edited by a moderator:
Physics news on Phys.org
Sounds like you're doing it right. You've got the forces broken down, solve for the unknowns. Make sure that you're assuming |AB| to be 700N not anyone component of it.
 
turns out working with unit vectors and i j and k is much easier! Thanks for the reply though!
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top