Energy in SHM: Practice Problem & Solution

Solution Explained:

To solve this problem, we apply the core principles of Energy in SHM. Understanding the underlying formula is key to arriving at the correct answer below:

$K.E. = \frac{1}{2} k (a^2 - x^2)$. At $x = a/2$, $K.E. = \frac{1}{2} k (a^2 - a^2/4) = \frac{3}{4} (\frac{1}{2} k a^2) = \frac{3}{4} E$.