A Weight Is Oscillating on the End of a Spring $y = \frac { 1 } { 12 } ( \cos 7 t - 3 \sin 7 t )$

question 25

Multiple Choice

A weight is oscillating on the end of a spring (see figure) .The position of the weight relative to the point of equilibrium is given by $y = \frac { 1 } { 12 } ( \cos 7 t - 3 \sin 7 t )$ ,where y is the displacement (in meters) and t is the time (in seconds) .Find the times when the weight is at the point of equilibrium (y = 0) for $0 \leq t \leq 1$ .​ ​ ​

• A)0.05sec,0.49sec,0.94sec
• B)0.05sec,0.05sec,0.94sec
• C)-0.40sec,0.49sec,0.94sec
• D)-0.40sec,0.49sec,-0.40sec
• E)0.05sec,-0.40sec,0.94sec