Posted by Amanda on .
An object is being acted upon by three forces and moves with a constant velocity. One force is 60N along the x-axis, the second force is 75N along a direction making a counterclockwise angle of 150 degrees with the x-axis. What is the direction of the third force, measured counterclockwise from the x-axis?
Add those two forces: (break them into x,y components). The third force will be equal and opposite to the sum of the first two.
F1+F2+F3 = M*a = M*0 = 0.
60 + 75[150o] + F3 = 0.
60 - 64.95+37.5i + F3 = 0.
F3 = 4.95 - 37.5i. = 37.8 N.[82.5o] N. of W. = 97.5o CCW from +x-axis.