Force F1 Resolved: Calculate Components & Magnitudes

AI Thread Summary
The discussion focuses on resolving force F1 into its components along the u and v axes, with the correct magnitudes being 205N for F1u and 160N for F1v. Participants clarify that the axes are not orthogonal and correct an initial mislabeling of angles, noting that the angle previously labeled as 60° is actually 40°. The resolution involves using the parallelogram law and the sine law to accurately calculate the components. One user successfully applies these methods to derive the correct values after receiving guidance. The conversation emphasizes the importance of understanding the relationships between the angles and the non-orthogonal nature of the axes.
savva
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Homework Statement


Resolve the force F1 into components acting along u and v axes and determine the magnitudes of the components. Refer to first attachment for full problem with diagram.

Homework Equations


asinθ
bcosθ

The Attempt at a Solution


Please refer to attachments for attempt at solution, drawings of diagram involved. Could not get the correct answer solving the way in which I attempted, can anybody give me a hand solving it, answers in the book were:
f1u=205N, f2v=160N
 

Attachments

  • Chp 2 - Q2.5 Problem0001.jpg
    Chp 2 - Q2.5 Problem0001.jpg
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  • Chp 2 - Q2.5 Problem0002.jpg
    Chp 2 - Q2.5 Problem0002.jpg
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  • Chp 2 - Q2.5 Problem0003.jpg
    Chp 2 - Q2.5 Problem0003.jpg
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savva said:

Homework Statement


Resolve the force F1 into components acting along u and v axes and determine the magnitudes of the components. Refer to first attachment for full problem with diagram.

Homework Equations


asinθ
bcosθ

The Attempt at a Solution


Please refer to attachments for attempt at solution, drawings of diagram involved. Could not get the correct answer solving the way in which I attempted, can anybody give me a hand solving it, answers in the book were:
f1u=205N, f2v=160N
The axes are not orthogonal.

The angle you have labeled as 60° is 40°. 30° + 40° = 70° .

(F1)v is a vector that's parallel to the v axis.

(F1)u is a vector that's parallel to the u axis.

(F1)v + (F1)u = F1

Superimpose an xy axis system onto the uv system, if that helps you.
 


SammyS said:
The axes are not orthogonal.

The angle you have labeled as 60° is 40°. 30° + 40° = 70° .

(F1)v is a vector that's parallel to the v axis.

(F1)u is a vector that's parallel to the u axis.

(F1)v + (F1)u = F1

Superimpose an xy axis system onto the uv system, if that helps you.

Sorry, tried using the information you have given and can't seem to solve it still
 


Start with force vector F1. Your last drawing has the required angles labelled. What are the expressions for the u component of F1 and the v component of F1? Remember that u and v are not orthogonal (not at 90° to each other), so while the projection on one axis may be Fcos(θ), the projection on the other axis won't be Fsin(θ). Choose appropriate angles and use the cosine.
 


I managed to solve it guys, thanks for your help.
I used the parallelogram law to split up the vector into components and used sin law to find relevant information, so:

300/sin110=v/sin30
v=sin^-1(300sin30/sin110) = 160N

300/sin110=u/sin40 ---> u=sin^-1(300sin40/sin110) = 205N

Cheers
 
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