Ex1

9 a
13 e
17 b
19 ?

1.

$$\tau GRF + \tau F_\text{flexors} = 0$$ $$F_\text{flexors} = \frac{GRF * .03}{.004} = GRF * 7.5$$ Straight: $$F_\text{flexors} = 120 * 7.5 = \boxed{900}$$ Cutting: $$F_\text{flexors} = 150 * 7.5 = \boxed{1125}$$

2.

Straight: $$JRF_x = \cos 20^\circ * 900 = 845.7$$ $$JRF_y = -\sin 20^\circ * 900 _ 120 = -427.8$$ $$JRF = \begin{pmatrix}845.7 \\ -427.8\end{pmatrix}$$

Cutting: $$JRF_x = \cos 10^\circ * 1125 = 1107.9$$ $$JRF_y = -\sin 10^\circ * 1125 - 150 = -345.4$$ $$JRF = \begin{pmatrix}1107.9 \\ -345.4\end{pmatrix}$$

3.

Straight: $$

Cutting: