Three particles of masses 100g, 150g, and 200g respectively are placed at the vertices of an equilateral triangle of a side 0.5 m long. What is the position of the centre of mass of three particles?

1.  $\left(\frac{5}{18}, \frac{1}{3\sqrt{3}}\right)$

2.  $\left(\frac{1}{4}, 0\right)$

3.  $\left(0, \frac{1}{4}\right)$

4.  $\left(\frac{1}{3\sqrt{3}}, \frac{5}{18}\right)$

Position of centre of mass of a triangular lamina as shown in the figure is:

What is the position of centre of mass of a uniform L-shaped lamina (a thin flat plate) with dimensions as shown? The mass of the lamina is 3 kg.

1.  $\left(\frac{6}{5}, \frac{6}{5}\right)$

2.  $\left(\frac{1}{5}, \frac{6}{5}\right)$

3.  $\left(\frac{5}{6}, \frac{5}{6}\right)$

4.  Can't be determined