Question

The coordinates of centre of mass of a uniform flag shaped lamina (thin flat plate) of mass $4\, kg$. (The coordinates of the same are shown in figure) are :

• A. (1.2 5m, 1.50 m )
• B. (0.75 m, 0.75 m)
• C. (0.75 m, 1.75 m)
• D. (1 m, 1.75 m)

Answer 1

The Correct Option is C

$m_{1}=3\,kg m_{2}=1\,kg$ Mass of plate-1 is assumed to be concentratedat $\left(0.5, 1.5\right)$ Mass of plate-2 is assumed to be concentratedat $\left(1.5, 2.5\right).$ $x_{cm}=\frac{m_{1}x_{1}+m_{2}x_{2}}{m_{1}+m_{2}}=\frac{3\times0.5+1\times1.5}{4}=0.75$ $y_{cm}=\frac{m_{1}y_{1}+m_{2}y_{2}}{m_{1}+m_{2}}=\frac{3\times 0.5+1\times 1.5}{4}=0.75$