6-51 할리데이 11판 솔루션 일반물리학

$$ \begin{cases} m&=1.20\ut{kg}\\ r&=20.0\ut{cm}\\ M&=3.00\ut{kg}\\ g&=9.80665\ut{m/s^2} \end{cases} $$ $$\Sigma F_R = \frac{mv^2}{R},$$ $$Mg=\frac{mv^2}{R}$$ $$ \begin{aligned} v&=\sqrt\frac{MgR}{m}\\ &=\sqrt{\frac{g}{2}}\\ &\approx 2.2143452756966333\ut{m/s}\\ &\approx 2.21\ut{m/s}\\ \end{aligned} $$