The tip of a prong of a tuning fork vibrates in SHM at 320 Hz with an amplitude of 0.6 mm…

Step 1. $\omega = 2\pi \times 320\ \text{Hz} = 2011\ \text{rad/s}$, and $A = 6 \times 10^{-4}\ \text{m}$.

Step 2. Speed. $v_{max} = 2011\ \text{rad/s} \times 6 \times 10^{-4}\ \text{m} = 1.21\ \text{m/s}$.

Step 3. Acceleration. $a_{max} = (2011\ \text{rad/s})^2 \times 6 \times 10^{-4}\ \text{m} = 2.43 \times 10^{3}\ \text{m/s}^2$, about $2430\ \text{m/s}^2$.

Step 4. Compare with $g$. $\dfrac{2.43 \times 10^{3}\ \text{m/s}^2}{9.8\ \text{m/s}^2} = 247$.