Why Does This Statics Problem Not Specify Resultant Force Direction?

Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
4 replies · 2K views
d0ntg3t1t
Messages
1
Reaction score
0

Homework Statement



http://imgur.com/a/FyekZ
I took the liberty of uploading everything. The first picture is the question, while the other two is my attempt at answering it in two parts. What I do not understand is what I did wrong or where I went wrong.
I also would like to know why, unlike many other questions from the text, this question does not specify in which direction the resultant force is directed. Is the question wrong, or am I supposed to go about this in a different manner?

EDIT: If you cannot see the full image, please click the gear icon (top right of each image - gear appears when you have the mouse over the image) and select view full resolution.

Homework Equations



See above.

The Attempt at a Solution



Please see above.
 
Physics news on Phys.org
Actually it looks like you can calculate the angle of the resultant. Call that β then..

In x..

FR*Cos(β) = F1*Cos(θ) - F2*3/5 + F3*Cos(45)
so
F1*Cos(θ) = FR*Cos(β) + F2*3/5 - F3*Cos(45) ...(1)

In y..

FR*Sin(β) = F1*Sin(θ) + F2*4/5 - F3*Sin(45)
so
F1*Sin(θ) = FR*Sin(β) - F2*4/5 + F3*Sin(45)...(2)


Knowns F2, F3, FR, θ
Unknowns F1 and β

We have two equations and two unknowns.