Consider an irregularly shaped planar lamina of uniform density rho , bounded by graphs x=f(y) , x=g(y) and c<=y<=d . The mass m of this region is given by:
m=rhoint_c^d(f(y)-g(y))dy
m=rhoA , where A is the area of the region
The moments about the x- and y-axes are given by:
M_x=rhoint_c^d y(f(y)-g(y))dy
M_y=rhoint_c^d 1/2([f(y)]^2-[g(y)]^2)dy
The center of mass (barx,bary) is given by:
barx=M_y/m
bary=M_x/m
We are given x=4-y^2 ,x=0
Refer to the attached image. The plot of x=4-y^2 is red in color.
Let's evaluate the area of the region,
A=int_(-2)^2(4-y^2)dy
A=2int_0^2(4-y^2)dy
A=2[4y-y^3/3]_0^2
A=2[4*2-2^3/3]
A=2[8-8/3]
A=32/3
M_y=2rhoint_0^2 1/2(4-y^2)^2dy
M_y=(2rho)/2int_0^2(4^2-2(4)y^2+(y^2)^2)dy
M_y=rhoint_0^2(16-8y^2+y^4)dy
M_y=rho[16y-8(y^3/3)+y^5/5]_0^2
M_y=rho[16*2-8/3(2^3)+1/5(2^5)]
M_y=rho[32-64/3+32/5]
M_y=rho[(480-320+96)/15]
M_y=256/15rho
By symmetry, M_x=0,bary=0
barx=M_y/m=M_y/(rhoA)
barx=(256/15rho)/(rho32/3)
barx=(256/15)(3/32)
barx=8/5
The coordinates of the center of mass are (barx,bary) are (8/5,0)
Monday, May 16, 2016
x=4-y^2 , x=0 Find the x and y moments of inertia and center of mass for the laminas of uniform density p bounded by the graphs of the equations.
Subscribe to:
Post Comments (Atom)
Why is the fact that the Americans are helping the Russians important?
In the late author Tom Clancy’s first novel, The Hunt for Red October, the assistance rendered to the Russians by the United States is impor...
-
Friar Lawrence plays a significant role in Romeo and Juliet's fate and is responsible not only for secretly marrying the two lovers but ...
-
Resourceful: Phileas Fogg doesn't let unexpected obstacles deter him. For example, when the railroad tracks all of a sudden end in India...
-
Pablo Neruda's "Ode to My Socks" is full of figurative language, including similes and metaphors. Similes are figurative compa...
-
In the late author Tom Clancy’s first novel, The Hunt for Red October, the assistance rendered to the Russians by the United States is impor...
-
At the beginning of the Victorian period, science was generally in accord with religion, and the study of nature was conducted in such a way...
-
Evaluate $\displaystyle \int x^2 \cos mx dx$ by using Integration by parts. If we let $u = x^2$ and $dv = \cos mx dx$, then $d...
-
Touching Spirit Bear by Ben Mikaelsen is a coming-of-age story about a young man named Cole who undergoes a healing treatment on a deserted ...
No comments:
Post a Comment