Step 1: SHM Equation
The displacement equation for SHM is:
\[\ny = A \sin (\omega t + \phi)\n\]
Where:
- \( y \) is displacement,
- \( A \) is amplitude,
- \( \omega \) is angular frequency,
- \( t \) is time,
- \( \phi \) is phase constant.
Given displacement equation:
\[\ny = 2 \sin \left( \frac{\pi}{2} + \phi \right) \, \text{cm}\n\]
Here, \( A = 2 \) cm, and \( \omega \) is \( \frac{\pi}{2} \).
Step 2: Maximum Acceleration Formula
Acceleration in SHM is:
\[\na = -\omega^2 y\n\]
Maximum acceleration occurs when \( y = A \):
\[\na_{\text{max}} = \omega^2 A\n\]
Step 3: Value Substitution
Known values:
- \( A = 2 \, \text{cm} \),
- \( \omega = \frac{\pi}{2} \).
Substitute into the maximum acceleration formula:
\[\na_{\text{max}} = \left( \frac{\pi}{2} \right)^2 \times 2\n\]
Simplifying:
\[\na_{\text{max}} = \frac{\pi^2}{4} \times 2 = \frac{\pi^2}{2} \, \text{cm/sec}^2\n\]
Step 4: Conclusion
Maximum acceleration is \( \frac{\pi^2}{2} \, \text{cm/sec}^2 \), which is:
\[\n\boxed{(A)} \, \frac{\pi^2}{2} \, \text{cm/sec}^2\n\]