11-23 할리데이 11판 솔루션 일반물리학

$$ \put \begin{cases} A : \text{Disk}\\ B : \text{Something}\\ \end{cases} $$ $$ \begin{cases} m_A&=0.10\ut{kg}\\ R&=0.10\ut{m}\\ \omega_{Ai} &= 4.7\ut{rad/s}\\ I_A&=5.0\times10^{-4}\ut{kg\cdot m^2}\\ m_B&=0.036\ut{kg} \end{cases} $$ $$I_B=m_BR^2,$$ $$\Delta \Sigma \vec L=0,$$ $$ \begin{aligned} 0&=\Delta \vec L_A+\Delta \vec L_B\\ &=\vec L_{Af}-\vec L_{Ai}+\vec L_{Bf}\\ &=\vec L_{f}-\vec L_{Ai}\\ &=\vec \omega_f\Sigma I-I_A\omega_{Ai}\\ \end{aligned} $$ $$ \begin{aligned} \vec \omega_f &=\frac{I_A}{\Sigma I}\omega_{Ai}\\ &=\frac{25}{43}\omega_{Ai}\\ &=\frac{235}{86}\ut{rad/s}\\ &\approx 2.7325581395348837\ut{rad/s}\\ &\approx 2.7\ut{rad/s}\\ \end{aligned} $$