Question 157: Centre of Mass and Rotational Motion

Question

The coordinates of centre of mass of a uniform
flag shaped lamina (thin flat plate) of mass 4kg.
(The coordinates of the same are shown in
figure) are :
![](https://imagex.cdn.examgoal.net/7k9k2k5gw62jq/dcc68ca3-eafb-49bb-b3a4-a2b0998cb3f0/408ef060-3875-11ea-92dd-4b9c3519996f/file-7k9k2k5gw62jr-311w.jpg)

Accepted Answer

m
1
= $\sigma $A
1
= $\sigma $$ 	imes $(1$ 	imes $2) = 2$\sigma $
m
2
= $\sigma $A
2
= $\sigma $$ 	imes $(2$ 	imes $1) = 2$\sigma $
$ 	herefore $ x
cm
= ${{{m_1}{x_1} + {m_2}{x_2}} \over {{m_1} + {m_2}}}$
= ${{2\sigma  	imes 0.5 + 2\sigma  	imes 1} \over {2\sigma  + 2\sigma }}$ = 0.75
and y
cm
= ${{{m_1}{y_1} + {m_2}{y_2}} \over {{m_1} + {m_2}}}$
= ${{2\sigma  	imes 1 + 2\sigma  	imes 2.5} \over {2\sigma  + 2\sigma }}$ = 1.75
![](https://imagex.cdn.examgoal.net/7kd4dk6pa6nbe/53393a91-f678-456f-83dc-ba0308629697/8cfbdea0-50de-11ea-b62d-51ccc5d4afb6/file-7kd4dk6pa6nbf-252w.png)

Answer

(0.75m, 1.75m)

Answer

(1m, 1.75m)

Answer

(0.75m, 0.75m)

Answer

(1.25m, 1.50m)

Centre of Mass and Rotational Motion

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

Choose the correct answer: