Answer:
0.33 s
Explanation:
For this case, as the object is hung on the end of an unstretched spring, we can consider this system as a simple pendulum.
For this system, we can determine the period of the motion using the following formula:
T = 2π√(L/g)
Where: T = period (in sec), L = lenght of the spring, g = acceleration of garvity = 9.8 m/s²
By the exact time the object is 2.75 cm before coming to rest, that will be the lenght of the spring we can consider (2.75 cm = 0.0275 m)
Finally:
T = 2π√(0.00275/9.8)
T = 0.33 sec