Physics help on vectors, please?

Question

three forces are applied to an object. Force F1 has a magnitude of 21.0 N and directed 30.0 degrees to the left of the positive x axis. Force F2 has a magnitude of 15.0 N and point along the positive axis. what must be the magnitude and direction of the third force f3 such that the vector sum of the three forces is 0 N?

Answer 1

Force F1 has a magnitude of 21.0 N and directed 30.0 degrees to the left of the positive x axis. Force F2 has a magnitude of 15.0 N and point along the positive axis. what must be the magnitude and direction of the third force f3 such that the vector sum of the three forces is 0 N?

Take the two vectors you have, find X and Y components, add them up, then negate the sum for the third vector.

"left of the positive x axis" is meaningless. I'll assume you mean above the x axis.

F1x = 21cos30

F1y = 21sin30

F2x =

I have to give up, too many ambiguities...

"point along the positive axis." which axis?

"left of the positive x axis" is meaningless. It has to be above or below.