Sebuah benda dilepaskan dari titik (1) dengan kelajuan 4 m/s seperti gambar di bawah ini.
Tentukan kecepatan benda di titik (2) dan titik (3)
Kecepatan di titik (2)
\begin{equation*}
\begin{split}
EM_1 & = EM_2 \\\\
EP_1 + EK_1 & = EP_2 + EK_2 \\\\
m \:.\: g \:.\: h_1 + \tfrac{1}{2} \:.\: m \:.\: v_1^2 & = m \:.\: g \:.\: h_2 + \tfrac{1}{2} \:.\: m \:.\: v_2^2 \\\\
\cancel {m} \:.\: g \:.\: h_1 + \tfrac{1}{2} \:.\: \cancel {m} \:.\: v_1^2 & = \cancel {m} \:.\: g \:.\: h_2 + \tfrac{1}{2} \:.\: \cancel {m} \:.\: v_2^2 \\\\
g \:.\: h_1 + \tfrac{1}{2} \:.\: v_1^2 & = g \:.\: h_2 + \tfrac{1}{2} \:.\: v_2^2 \\\\
10 \:.\: 8 + \tfrac{1}{2} \:.\: 4^2 & = 0 + \tfrac{1}{2} \:.\: v_2^2 \\\\
88 & = \tfrac{1}{2} \:.\: v_2^2 \\\\
v_2^2 & = 176 \\\\
v_2 & = 4 \sqrt{11} \text{ m/s}
\end{split}
\end{equation*}
Kecepatan di titik (3)
\begin{equation*}
\begin{split}
EM_1 & = EM_2 \\\\
EP_1 + EK_1 & = EP_2 + EK_2 \\\\
m \:.\: g \:.\: h_1 + \tfrac{1}{2} \:.\: m \:.\: v_1^2 & = m \:.\: g \:.\: h_2 + \tfrac{1}{2} \:.\: m \:.\: v_2^2 \\\\
\cancel {m} \:.\: g \:.\: h_1 + \tfrac{1}{2} \:.\: \cancel {m} \:.\: v_1^2 & = \cancel {m} \:.\: g \:.\: h_3 + \tfrac{1}{2} \:.\: \cancel {m} \:.\: v_3^2 \\\\
g \:.\: h_1 + \tfrac{1}{2} \:.\: v_1^2 & = g \:.\: h_3 + \tfrac{1}{2} \:.\: v_3^2 \\\\
10 \:.\: 8 + \tfrac{1}{2} \:.\: 4^2 & = 10 \:.\: 5 + \tfrac{1}{2} \:.\: v_3^2 \\\\
38 & = \tfrac{1}{2} \:.\: v_3^2 \\\\
v_2^2 & = 76 \\\\
v_2 & = 2 \sqrt{19} \text{ m/s}
\end{split}
\end{equation*}