A telescopic light pole is being extended so that its height increases at

MATHEMATICS · Single correct · AP · Calculus AB · Contextual Applications of Differentiation · Contextual Applications of Differentiation

Problem

0.2\text{ ft/s}

. Simultaneously, a

6

-ft tall skateboarder moves directly away from the base of the pole at

5\text{ ft/s}

. When the pole is

18\text{ ft}

tall and the skateboarder is

12\text{ ft}

from the base, what is the speed of the tip of the skateboarder’s shadow? (a)

5.0\text{ ft/s}

(b)

8.9\text{ ft/s}

(c)

7.4\text{ ft/s}

(d)

6.6\text{ ft/s}