11-29 할리데이 11판 솔루션 일반물리학

$$\vec \tau_\net=\dyt{\vec L},$$ $$\ab{a}$$ $$\vec L=-6.5\k\ut{kg\cdot m^2/s},$$ $$ \begin{aligned} \vec \tau_\net&=\dyt{\vec L}=0 \end{aligned} $$ $$\ab{b}$$ $$\vec L=-6.5t^2\k\ut{kg\cdot m^2/s},$$ $$ \begin{aligned} \vec \tau_\net&=\dyt{\vec L}=-13t\k\ut{N\cdot m} \end{aligned} $$ $$\ab{c}$$ $$\vec L=-6.5\sqrt t\ut{kg\cdot m^2/s},$$ $$ \begin{aligned} \vec \tau_\net&=\dyt{\vec L}=-{13\over4\sqrt t}\k\ut{N\cdot m} \end{aligned} $$ $$\ab{d}$$ $$\vec L=-{6.5\over t^2}\ut{kg\cdot m^2/s},$$ $$ \begin{aligned} \vec \tau_\net&=\dyt{\vec L}={13\over t^3}\k\ut{N\cdot m} \end{aligned} $$