Question

What size force does the femur exerts on the kneecap if the tendons are oriented as in the figure and the tension in each tendon is 60 N?

Answer 1

http://session.masteringphysics.com/problemAsset/1168048/2/jfk.Figure.05.U32EOC.jpg

Answer 2

I got the answer of 66.934, but that wasn't right.

Answer 3

what i did so far

Answer 4

i have to go to work, but i will be back in 2 hours

Answer 5

\[
\begin{array}{ccccc}
F_x &=& 60\cos(90^{\circ}) + 60\cos(40^{\circ})\\
F_y &=& 60\sin(90^{\circ}) + 60\sin(40^{\circ})\\
|F| &=& \sqrt{F_x^2+F_y^2}
\end{array}
\]

Answer 6

Got the wrong answer (which I got as 108.75 N)