Answer:
6 rad/s
Step-by-step explanation:
In a spring the angular frequency is calculated as follows:

where
is the angular frequency,
is the mass of the object in this case
, and
is the constant of the spring.
To calculate the angular frequency, first we need to find the constant
which is calculated as follows:

Where
is the force:
, and
is the distance from the equilibrium position:
.
Thus the spring constant:


And now we do have everything necessary to calculate the angular frequency:


the angular frequency of the oscillation is 6 rad/s