Question

Which of these physical settings makes sense for an object moving along the x-axis? Its position at any time is given by x(t) = 3cos(π t) + 2

a. A skydiver falling from a plane, before she opens her parachute.

b. The shadow cast by a rock that's stuck on the edge of a spinning wheel.

c. A car driving from San Diego to Los Angeles.

d. An ant walking at a steady pace from the tip of a propeller toward the hub.

e. None of these settings.

Answer 1

cosine is an oscillating function, meaning it gets bigger, then smaller, over and over. It is called a circular function because it models the location of a point on a rolling circle.

so, what do you think?

Answer 2

probably b, right?

Answer 3

yes, probably b, as silly as the example is.

Answer 4

The shadow cast