Solve the Problem $s ( t ) = - 3 \cos 7 \pi t$

question 156

Multiple Choice

Solve the problem.
-The position of a weight attached to a spring is $s ( t ) = - 3 \cos 7 \pi t$ inches after $t$ seconds. When does the weight first reach its maximum height?

• A) After \(\frac { \pi } { 7 } \mathrm { sec }\)
• B) After \(\frac { 1 } { 7 } \mathrm { sec }\)
• C) After \(\frac { 7 } { \pi } \mathrm { sec }\)
• D) After \(\frac { 7 } { 4 } \mathrm { sec }\)