Step 1: Acceleration in SHM.
In simple harmonic motion (SHM), the acceleration \( a \) is related to the displacement \( x \) from the mean position by the equation:
\[
a = - \omega^2 x
\]
where \( \omega \) is the angular frequency and \( x \) is the displacement.
Step 2: Use the given data.
We are given:
- \( a = 12 \, \text{cm/s}^2 = 0.12 \, \text{m/s}^2 \)
- \( x = 3 \, \text{cm} = 0.03 \, \text{m} \)
Substitute these values into the SHM equation:
\[
0.12 = \omega^2 \times 0.03
\]
Step 3: Solve for angular frequency \( \omega \).
Rearranging the equation:
\[
\omega^2 = \frac{0.12}{0.03} = 4
\]
\[
\omega = 2 \, \text{rad/s}
\]
Step 4: Calculate the time period.
The time period \( T \) of the particle is related to the angular frequency by the formula:
\[
T = \frac{2\pi}{\omega}
\]
Substitute \( \omega = 2 \, \text{rad/s} \):
\[
T = \frac{2\pi}{2} = \pi \, \text{seconds}
\]
Thus, the time period is approximately \( 3.14 \, \text{seconds} \).
Step 5: Conclusion.
Therefore, the time period is \( 3.14 \, \text{seconds} \).