If F_B = 2kN and the resultant force acts along the positive u axis, determine the magnitude of the resultant force and the angle u.

#### Solution:

### Let us first draw the vector components as follows:

### Notice thatÂ the resultant is along the u-axis as stated by the question.

### Now, we will draw the vector components tail to tail as follows:

### We can now use law of sines to figure out \phi. (Forgot the law of sines?)

### \frac{\sin \phi}{3}=\frac{\sin30^0}{2}

### \phi=48.69^0

### From this, we can figure out \theta.

### \theta=30^0+\phi

### \theta = 78.59^0

Is there any another way to slove it ? and if there is how we can do it ? Thanks

I am sure there are other ways to solve these types of questions though I haven’t utilized them. Most textbooks usually show two ways of solving these questions, either the tip to tip method or the parallelogram way. Please take a look: https://goo.gl/ssjJMP

Many thanks and best of luck with your studies. đŸ™‚