Answer
The coordinates of the center of mass are:
(0.0444 m, 0.0555 m)
Work Step by Step
$x_{cm} = \frac{m_1x_1+m_2x_2+m_3x_3}{m_1+m_2+m_3}$
$x_{cm} = \frac{(0.300~kg)(0.200~m)+(0.400~kg)(0.100~m)+(0.200~kg)(-0.300~m)}{0.300~kg+0.400~kg+0.200~kg}$
$x_{cm} = 0.0444~m$
$y_{cm} = \frac{m_1y_1+m_2y_2+m_3y_3}{m_1+m_2+m_3}$
$y_{cm} = \frac{(0.300~kg)(0.300~m)+(0.400~kg)(-0.400~m)+(0.200~kg)(0.600~m)}{0.300~kg+0.400~kg+0.200~kg}$
$y_{cm} = 0.0555~m$
The coordinates of the center of mass are:
(0.0444 m, 0.0555 m)
