A particle travels along the circle of radius according to for

MATHEMATICS · Single correct · AP · Calculus BC · Parametric, Polar, and Vector-Valued Functions · Parametric, Polar, and Vector-Valued Functions

Problem

A particle travels along the circle of radius

5

according to

\mathbf{r}(t)=\langle 5\cos t, 5\sin t\rangle

for

0 \le t \le \pi

. What is the particle’s average speed on this interval? (a)

5\pi\,\text{units}\,\text{s}^{-1}

(b)

\frac{10}{\pi}\,\text{units}\,\text{s}^{-1}

(c)

5\,\text{units}\,\text{s}^{-1}

(d)

25\,\text{units}\,\text{s}^{-1}