I happen to face this question in an exam paper. The question is phrased as:
A block of mass $m$ is released from the top of fixed inclined smooth place. If $\theta$ is the angle of inclination, then the vertical acceleration of the block is?
I know that the gravitational acceleration is $g$ (vertically downwards) or $g\sin(\theta)$ along the direction of the inclined plane.
But the answer key I got with the paper read that the correct answer is $g\sin^2(\theta)$. Am I missing something or is the answer key simply wrong?
I mean, I have resolved the components of gravity and no value signifies $g\sin^2(\theta)$.