Determine Resultant Force-Couple on T6 Vertebra at F2

[pinksunbeam]

Homework Statement

A chiropractor applies a thrust to the spinous process of T6. The magnitude is 400 N and it is applied 90 degrees to the y-axis. While this occurs the superior disc applies a force to the T6 body of 615 N, 75 degrees to the x-axis. The inferior disc applies a force to the T6 body of 620 N, 70 degrees to the x-axis. Determine the resultant force-couple acting on the T6 vertebra at the point of application F2. The coordinates of the points of application for each force are shown in brackets.

Homework Equations

moment= force by perpendicular distance

The Attempt at a Solution

need to get moments first. I am don't think i did this right but i moved f1 and f3 to f2 and got moment there.
f1=.063x400= 38.75 N.m
f2=.018x620=9.92N.m

is this right way to get the moment for this question? i believe I am doing something wrong with distance

 

[pinksunbeam]

Homework Statement

A chiropractor applies a thrust to the spinous process of T6. The magnitude is 400 N and it is applied 90 degrees to the y-axis. While this occurs the superior disc applies a force to the T6 body of 615 N, 75 degrees to the x-axis. The inferior disc applies a force to the T6 body of 620 N, 70 degrees to the x-axis. Determine the resultant force-couple acting on the T6 vertebra at the point of application F2. The coordinates of the points of application for each force are shown in brackets.

Homework Equations

moment= force by perpendicular distance

The Attempt at a Solution

need to get moments first. I am don't think i did this right but i broke f1 and f3 into x and y components. subtracted from f2 to get perpendicular distance.
f1x=.0125 f1y=- .062
f3x=.02 f3y=-.002

then get moments
f1
-7nm, no y its on x axis

f3x= 4.24nm, f3y= 1.17nm. i did 620cos70 perpend D for x and 620sin70 PD for y.
resultant moment add all
-7+4.24+1.17= -1.59 Nm

move all to f2 get resultant force and angle.
f1x= -400n f1y=o
f2x= 615cos75=159.17n
f2y=615sin75=-594,04n
f3x=620cos70=212.05n f3y=620nsin70= 582.61N
add all xs= -28.78N add all ys= -11.43N

resultant angle
c2=a2+b2
use total for x and y=
30.97N

for angle
tan-1 fy/fx=
11.43/28.78= .397
tan-1= 21.66 degrees .