ANSWERS TO QUESTIONS IN "YOUR OWN PHYSICS COMPANION"

1. 2A=6i-2j-8k

   -B=2i-4j+3k

   3C=3i+6j-3k

   R=11i+0j-8k

2. |3A-2B+4C|

   3A=9i-3j-12k

   -2b=4i-8j+6k

   4C=4i+8j-4k

   R=17i-3j-10k

3. Let the unitary vector be r r=R/|R|

   =(17i-3j-10k)/19.95

   r=(340/399)i-(20/133)j-(200/399)k