HY 607: Finding the Angle for Resultant Force of Two Forces

[lektor]

with reference to the diagram, at what angle must the 800N force be applied in order that the resultant R of the two forces has a magnitude of 2000N.

We were instructed to use the i,j method.

So, the forces for Fi = 800sin(-) and Fj = 1400 + 800 cos(-) and the resultant is 2000N.

This is where i get stuck, a^2 + b^2 = c^2
so 2000^2 = (800 sin(-))^2 + (1400+800 cos(-))^2

any help would be great.

 

[lektor]

bump^

please help :p

 

[Hootenanny]

bump^

please help :p

We can't see the attachment yet...

 

[lektor]

it is simply a diagram showing

|.../
|.../
|(-)./
|.../
|./

with the vertical line saying 1400N and the diagonal line saying 800N

 

[mukundpa]

It appears correct, expand

2000^2= 800^2 sin^2(@) + 1400^2 +2*1400*800*cos@ + 800^2*cos^2@

2000^2 - 800^2 - 1400^2 = 2*1400*800*cos@

solve for cos@


MP