Vectors

[muskan]

6 th please!

[DrKrettin]

You have two equations and 3 unknowns.

 

1) resolve along the y axis

 

2) resolve along the x axis

 

Eliminate F1 and you get an equation of the form F2. f(theta) = constant

 

F2 is a minimum when f(theta) is a maximum. So differentiate f(theta) and you get a turning point (assume maximum) for a value of theta. Then you get F1 and F2.

 

Does that help?

[Function]

 

6 th please!

 

Pardon me? This isn't a Q&A

 

House rules dictate you must show us what work you've done yourself already in order to solve the problem ...DrK was very generous in already giving you some hints etc. so you might just skip that.

 

Anyway, just noting that in the future, you might just want to show us what you know on the subject and on the specific problem. We don't know what your strengths/weaknesses are and if we don't know these, we can't form a "personal fitted" answer.

Edited May 9, 2017 by Function

[muskan]

how can we eliminate f1?

this is what i have done

[DrKrettin]

how can we eliminate f1?

 

 

It looks like you have the two equations correct. (It's too unclear to be sure) Resolving along the x-axis you have F2.sin(theta) = F1.cos 30

 

From that, F1 = F2.sin(theta)/cos 30

 

In the other equation resolving along the y-axis, use this to replace F1 with F2.sin(theta)/cos 30

 

Rearrange that and you get an equation of the form F2. f(theta) = constant, as I mentioned above. Then proceed as stated.

Edited May 10, 2017 by DrKrettin