Math
posted by Hannah on .
Three forces with magnitudes of 70 pounds, 40 pounds, and 60 pounds act on an object at angles of 30 degrees, 45 degrees, and 135 degrees, respectively, with the positive xaxis. Find the direction and manitude of the resultant of these forces.
Please explain. I really do not understand these.

The three vectors can be written as
(70cos(30),70sin(30)) or (60.622, 35)
(40cos45,40sin45), or (28.2843, 28.2843)
(60cos135,60sin135) or 42.4264, 42.4264)
so the sum of those three vectors is
(46.4799, 35.7107)
the magnitude of that is
√(46.4799^2 + 35.7107^2) = 58.614
the direction would be arctan(35.7107/46.4799) = 37.535° 
Thank You!

THE SAME AS HANNAH!