Solve the problem.
-The position of a weight attached to a spring is $s ( t ) = - 5 \cos 5 \pi t$ inches after $t$ seconds. When does the weight first reach its maximum height?
A) After $\frac { 5 } { 4 } \mathrm { sec }$
B) After $\frac { 1 } { 5 } \sec$
C) After $\frac { \pi } { 5 } \sec$
D) After -

Question

Quizplus · Accepted Answer

The maximum height is reached when the cosine function equals 1, which happens at $t = 0$. Since the cosine function has a period of $\frac{2\pi}{5\pi} = \frac{2}{5}$ seconds, the first maximum after $t = 0$ occurs at $\frac{1}{5}$ of the period, which is $\frac{1}{5} \times \frac{2}{5} = \frac{2}{25} = \frac{1}{5}$ seconds.

Solve the Problem s(t)=−5cos⁡5πts ( t ) = - 5 \cos 5 \pi ts(t)=−5cos5πt

Solve the Problem $s ( t ) = - 5 \cos 5 \pi t$