Chapter 11, Problem 25P

SSM Force $\stackrel{\to }{F}=\left(-8.0\text{N}\right)\hat{i}+\left(\text{6}\text{.0}\text{N}\right)\hat{j}$ acts on a particle with position vector $\stackrel{\to }{r}=\left(3.0\text{m}\right)\hat{i}+\left(4.0\text{m}\right)\hat{j}$. What are (a) the torque on the particle about the origin, in unit-vector notation, and (b) the angle between the directions of $\stackrel{\to }{r}$ and $\stackrel{\to }{F}$?