Answer
7.55N
Work Step by Step
Because both pulls have both equal magnitudes and angles relative to the patient's arm, each pull will contribute half of the horizontal force. So, if both pulls together must contribute 12.8N on the patient's arm, each one must contribute 6.4N.
We can create a right triangle out of each pull, with the pull being the hypotenuse, and the horizontal an vertical components being the legs. So, if we know that the hypotenuse has a value of 6.4N and that it makes a 32 degree angle with the horizontal leg, and we want to find the value of the horizontal leg(x), we can say:
cos(32) = 6.4/x
so
x = 6.4/cos(32)
x = 7.55N
