# Homework Help: Determine the magnitude of the resultant force

1. May 15, 2010

### Precursor

The problem statement, all variables and given/known data
If $$F_{B} = 5kN$$ and the resultant force acts along the positive u axis, determine the magnitude of the resultant force.

The attempt at a solution

$$F_{Rx} = F_{R}cos 30$$

$$F_{Ry} = F_{R}sin 30$$

$$F_{Rx} = 3 + 5cos\theta$$

$$F_{Ry} = 5sin\theta$$

Therefore, $$\frac{3 + 5cos\theta}{5sin\theta} = \sqrt{3}$$

Is this correct so far? I don't know how to isolate $$\theta$$

Last edited: May 15, 2010
2. May 15, 2010

### diazona

What variable is the problem asking you to find?

3. May 15, 2010

### Precursor

It is asking for the resultant force which acts along the u axis.

4. May 15, 2010

### Winzer

That is right so you don't have to find $$\theta$$

5. May 15, 2010

### Precursor

Then how would I go about finding the resultant force? Using a combination of the equations I posted in my attempt?

6. May 15, 2010

### diazona

Yep. I asked which variable the question was asking for for a reason; make sure you know which variable you need to find the value of and don't let it disappear when you combine the equations.

7. May 15, 2010

### Precursor

But I still don't see how I can solve for the resultant force without first solving for theta. Am I missing something?