高校物理 力学 ~ 剛体のつり合い
力のモーメント (moment of force)
\begin{eqnarray*}
M &=& Fh = FL \sin \theta \\
\\
\vec{M} &=& \vec{L} \times \vec{F} \\
\\
|\vec{M}| &=& |\vec{L}| |\vec{F}| \sin \theta = FL \sin \theta
\end{eqnarray*}
M &=& Fh = FL \sin \theta \\
\\
\vec{M} &=& \vec{L} \times \vec{F} \\
\\
|\vec{M}| &=& |\vec{L}| |\vec{F}| \sin \theta = FL \sin \theta
\end{eqnarray*}
M &=& Fh = FL \sin \theta
\vec{M} &=& \vec{L} \times \vec{F}
|\vec{M}| &=& |\vec{L}| |\vec{F}| \sin \theta = FL \sin \theta
重心 (center of gravity)
\begin{eqnarray*}
x_G &=& \frac{m_1 x_1 + m_2 x_2 + m_3 x_3 + \cdots + m_n x_n}{m_1 + m_2 +m_3 + \cdots + m_n} \\
\\
y_G &=& \frac{m_1 y_1 + m_2 y_2 + m_3 y_3 + \cdots + m_n y_n}{m_1 + m_2 +m_3 + \cdots + m_n} \\
\end{eqnarray*}
x_G &=& \frac{m_1 x_1 + m_2 x_2 + m_3 x_3 + \cdots + m_n x_n}{m_1 + m_2 +m_3 + \cdots + m_n} \\
\\
y_G &=& \frac{m_1 y_1 + m_2 y_2 + m_3 y_3 + \cdots + m_n y_n}{m_1 + m_2 +m_3 + \cdots + m_n} \\
\end{eqnarray*}
x_G = \frac{m_1 x_1 + m_2 x_2 + m_3 x_3 + \cdots + m_n x_n}{m_1 + m_2 +m_3 + \cdots + m_n}
y_G = \frac{m_1 y_1 + m_2 y_2 + m_3 y_3 + \cdots + m_n y_n}{m_1 + m_2 +m_3 + \cdots + m_n}