$\text { A buoy oscillates in simple harmonic motion } y = A \cos \text { at as waves move past }$

Multiple Choice

$\text { A buoy oscillates in simple harmonic motion } y = A \cos \text { at as waves move past }$ it. The buoy moves a total of $13.5$ feet (vertically) between its low point and its high point. It returns to its high point every 10 seconds. Determine the velocity of the buoy as a function of $t$ .

A) $v = - 6.75 \pi \sin \frac { \pi } { 10 } t$
B) $v = 6.75 \pi \sin \frac { \pi } { 5 } t$
C) $v = - 1.35 \pi \sin \frac { \pi } { 5 } t$
D) $v = - 1.35 \pi \sin \frac { \pi } { 10 } t$
E) $v = 1.35 \pi \sin \frac { \pi } { 5 } t$