Chapter 11.2, Problem 13E

How long is the shadow cast by a 540-foot tower when the sun's rays follow the vector [6,10,-27]? Also, at what angle do the rays of the sun strike the ground?

What is the component for the vector pictured on the right?

Zha begins 7 kilometers to the north of town, and rides his bike along a straight trail which leads to a park 3 kilometers west of town. He takes 20 minutes to cover this distance. • Write a vector in component form describing Zha's bike ride. • Find the magnitude and direction of this vector. • Find the component of Zha's motion which is in the direction "southwest". (Use a unit vector to represent this direction.) Use both forms of the dot product (algebraic and geometric) to compute this, and compare to be sure you get the same answer both ways.