A body of mass 5.0 kg is suspended by a spring which stretches 10 cm when the mass is attached. It is then displaced downward an additional 5.0 cm and released. Its position as a function of time is approximately
A)y = −0.10 sin 9.9t.
B)y = 0.10 cos 9.9t.
C)y = −0.10 cos (9.9t + 0.1).
D)y = 0.10 sin (9.9t + 5).
E)y = −0.05 cos 9.9t.

Question

Quizplus · Accepted Answer

The spring stretches 10 cm under the weight of the mass, indicating the equilibrium position. The additional 5 cm displacement is the amplitude of oscillation. The position function should reflect this amplitude and the negative cosine function indicates starting from the maximum displacement.

A Body of Mass 5