Question

The resultant of two forces acting on a body has a magnitude of 80 pounds. The angles between the resultant and the forces are 20° and 52°. Find the magnitude of the larger force.

Answer 1

Say you had these two vectors

Answer 2

The resultant can be found using the parallelogram law for vectors



the basic idea is that you form a parallelogram with those two vectors as the two different side lengths

another way to see it: start at the tip of one vector and move in the same direction as the other vector (and the same length as the other vector)

Answer 3

However, you see it, the resultant is this new vector

Answer 4

now fill in the given info

Answer 5

the question now is, how do we find angle y?

Answer 6

any ideas?

Answer 7

Use the Law of Sines to figure it out?

Answer 8

yes but you need angle y first

Answer 9

I don't know how I would find that :l

Answer 10

once you have angle y, you can use it to find x (using the law of sines)



because you'll basically have this triangle