The displacement from equilibrium of an oscillating weight suspended by a spring is given by $y ( t ) = 3 \cos 10 t$ ,where y is the displacement in centimeters and t is the time in seconds.Find the displacement when $t = 0.65$ ,rounding answer to four decimal places.
A)-3.7018 cm
B)-6.4350 cm
C)23.8825 cm
D)2.9298 cm
E)-1.6362 cm

Question

Quizplus · Accepted Answer

To find the displacement at $t = 0.65$, substitute $t$ into the equation: $y(0.65) = 3 \cos(10 \times 0.65)$. Calculate $y(0.65) = 3 \cos(6.5)$. Using a calculator, $\cos(6.5) \approx 0.9766$. Thus, $y(0.65) = 3 \times 0.9766 \approx 2.9298$.

The Displacement from Equilibrium of an Oscillating Weight Suspended by a Spring