Physics: Trigonometry

1. Jan 25, 2005

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.

2. Jan 25, 2005

dextercioby

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

Daniel.

3. Jan 25, 2005

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).

4. Jan 25, 2005

Staff: Mentor

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? :uhh:

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

5. Jan 25, 2005

shawonna23

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

6. Jan 25, 2005

dextercioby

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

Daniel.