A plane lamina with constant density $\rho ( x , y ) = 12$ occupies a region in the $x y$-plane bounded by a simple closed path $C$. Its moments of inertia about the axes are
$$l _ { x } = - \frac { \rho } { 3 } \int _ { C } y ^ { 3 } d x \text { and } l _ { y } = \frac { \rho } { 3 } \int _ { C } x ^ { 3 } d y$$
Find the moments of inertia about the axes, if $C$ is a rectangle with vertices $( 0,0 ) , ( 4,0 )$, $( 4,5 )$ and $( 0,5 ) .$
A) $( - 1,280,1,280 )$
B) $( - 2,880,1,200 )$
C) $( 2,000 , - 1,280 )$
D) $( 2000,1280 )$
E) $( - 2,000,1,280 )$

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The Answer of A plane lamina with constant density $\rho ( x , y ) = 12$ occupies a region in the $x y$-plane bounded by a simple closed path $C$. Its moments of inertia about the axes are
$$l _ { x } = - \frac { \rho } { 3 } \int _ { C } y ^ { 3 } d x \text { and } l _ { y } = \frac { \rho } { 3 } \int _ { C } x ^ { 3 } d y$$
Find the moments of inertia about the axes, if $C$ is a rectangle with vertices $( 0,0 ) , ( 4,0 )$, $( 4,5 )$ and $( 0,5 ) .$
A) $( - 1,280,1,280 )$
B) $( - 2,880,1,200 )$
C) $( 2,000 , - 1,280 )$
D) $( 2000,1280 )$
E) $( - 2,000,1,280 )$

A Plane Lamina with Constant Density ρ(x,y)=12\rho ( x , y ) = 12ρ(x,y)=12

A Plane Lamina with Constant Density $\rho ( x , y ) = 12$