Finding the Magnitude and Direction of a Force Vector Using Trigonometry

[shawonna23]

A force vector F1 points due east and has a magnitude of 200N. A second force F2 is added to F1. The resultant of the two vectors has a magnitude of 400N and points along the east/west line. Find the magnitude and direction of F2.

i really don't know what equation I would use to solve this problem.

 

[dextercioby]

Write the addition of vectors and then chose 2 axes of coordinates and project it...

Daniel.

 

[BobG]

What are your choices for equations?

A vector pointing due East lies on the East/West line. This winds up being the same as doing arithmetic on a number line. You only have two choices for directions (East or West). Each direction would give you a different magnitude. (Double check to see if they specified which direction the resultant was pointing).

 

[jtbell]

A force vector F1 points due east and has a magnitude of 200N. A second force F2 is added to F1. The resultant of the two vectors has a magnitude of 400N and points along the east/west line. Find the magnitude and direction of F2.

They're telling you that

$$\bold {F}_1 + \bold {F}_2 = \bold {R}$$

They're giving you the values of $$\bold {F}_1$$ and $$\bold {R}$$.

So in order to find $$\bold {F}_2$$ you need to do this:

$$\bold {F}_2 = \bold {R} - \bold {F}_1$$.

Now, if you've learned how to add two vectors by now, how would you modify the procedure so as to subtract them instead of add them?

If you haven't learned how to add two vectors by now, I suggest you go back and do that before tackling this problem.

 

[shawonna23]

Thanks for the help. I think the answers are 200N due east and 600N due west

 

[dextercioby]

Yes,the answers are correct.We only hope u've gotten them through a correct method...

Daniel.