Bidang Miring

(A)   Besar gaya normal

\begin{equation*}
\begin{split}
\Sigma F_y & = 0 \\\\
N - w \:.\: \cos \theta & = 0 \\\\
N & = mg \:.\: \cos \theta
\end{split}
\end{equation*}

(B)   Besar percepatan balok

\begin{equation*}
\begin{split}
\Sigma F_x & = m \:.\: a \\\\
w \:.\: \sin \theta & = m \:.\: a \\\\
\cancel {m}g \:.\: \sin \theta & = \cancel {m} \:.\: a \\\\
g \:.\: \sin \theta & = a
\end{split}
\end{equation*}