Chapter 4, Problem 42P

Using motion capture, the positions P₁ and P₂ of each arm segment arc measured while a person throws a ball. The length from shoulder to elbow $\left(P_1\right)$ is 10 in, and the length from elbow to the hand holding the bail $\left(P_2\right)$ is 13 in. The angle ${\theta }_1$ is 60° and ${\theta }_2$ is 65.

(a) Using the x-y coordinate system shown in Fig. P4.42. write the position of the ball $\stackrel{\to }{P}=\stackrel{\to }{P_1}+\stackrel{\to }{P_2}$ in standard vector notation.

(b) Determine both the magnitude and direction of $\stackrel{\to }{P}$.