1 \begin{problem*}{10.35}
2 Find the net torque on the wheel in Figure~P10.35 about the axle
3 through $O$, taking $a=10.0\U{cm}$ and $b=25.0\U{cm}$.
4 % 10.0N at a point b N of O, pulling E
5 % 9.00N at a point b E of O, pulling S
6 % 12.0N at a point a ~NW of O, pulling tangentially 30dg S of W.
10 Taking the positive direction to be counter clockwise and summing the
11 torque $\tau = \vect{r}\times\vect{F}$:
13 \sum \tau = 12.0\U{N}\cdot a - 10.0\U{N}\cdot b - 9.00\U{N}\cdot b
16 We don't care about the $30\dg$ angle (where the force is applied).
17 What matters is the distance from the axle to the force ($a$) and the
18 angle between the radius and force ($90\dg$).