Attraction force of material curves and lines

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Mass MM is uniformly distributed over the upper half (y⩾0y\geqslant 0) of the circle x2+y2=a2x^{2}+y^{2}=a^{2}. With what force does it attract a point mass mm located at (0,0)(0,0)?

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A homogeneous rod of length 2a2 a has mass MM. A material point of mass mm is located on the perpendicular bisector of from the rod at distance bb from its midpoint. With what force does the rod attract the point?

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A homogeneous infinite rod has linear density ρ\rho. A material point of mass mm is located at distance ll from the rod. With what force does the rod attract the point?

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The leg ABA B of a right triangle ABC  (∠A=90∘)A B C \; (\angle A = 90^{\circ }) is a homogeneous material rod of length 4a4 a and mass MM. At the vertex CC a material point of mass mm is placed, AC=3aA C = 3 a:

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(1)

find the force with which the rod ABA B attracts the point CC;

(2)

at what point of the rod ABA B should a material point be placed, and of what mass, so that it attracts the point CC with the same force as the rod ABA B?

A homogeneous infinite rod with linear density ρ\rho is bent into the shape of an angle. On the line containing the bisector of this angle there is a material point of mass mm at distance hh from the vertex of the angle. With what force does the rod attract the point?

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In the Cartesian coordinate system OxyO x y a material line is given by the equation y=0y = 0; its linear density varies according to the law ρ(x)=α∣x∣,α>0\rho (x) = \alpha \left|x\right|, \alpha > 0. With what force does this line attract a point of mass mm located on the ordinate axis?

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With what force does a homogeneous material half-ring of mass MM and radius rr attract a material point of mass mm located at its center?

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A material circle has linear density ρ\rho and radius rr. On the perpendicular to the plane of the circle passing through its center there is a material point of mass mm at distance aa from the center. With what force does the circle attract the point?

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On the unit circle x=cos⁡φ,y=sin⁡φ,0⩽φ⩽2πx = \cos \varphi , y = \sin \varphi , 0 \leqslant \varphi \leqslant 2 \pi, a charge is distributed with linear density

ρ(φ)=∣sin⁡φ∣a−cos⁡φ,a>1 \rho (\varphi ) = \frac{\left|\sin \varphi \right|}{a-\cos \varphi }, \quad a > 1

At the point (a;0)(a ; 0) there is a charge qq. Find the force acting on this charge.

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Prove, starting from the law of interaction of point masses, that a material curve Γ\Gamma with linear density ρ(ξ;η;ζ)\rho (\xi ; \eta ; \zeta ) attracts a mass mm located at the point M(x;y;z)M(x ; y ; z) with force

F=km∫ΓMN‾∣MN‾∣3ρ(ξ;η;ζ)dx,N=N(ξ;η;ζ) \mathbf{F} = k m \int _{\Gamma } \frac{\overline{M N}}{|\overline{M N}|^{3}} \rho (\xi ; \eta ; \zeta ) d x, \quad N = N(\xi ; \eta ; \zeta )
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Find the intensity of the gravitational field created by a homogeneous material line with linear density ρ0\rho_{0}.

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With what force does a mass MM, uniformly distributed along the circle x2+y2=a2,z=h>0x^{2}+y^{2} = a^{2}, z = h > 0, attract a point mass mm placed at the origin.

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References

[Dem97] Demidovich B.P. Сборник задач и упражнений по математическому анализу. 13-е изд., Издательство Московского университета / Издательство "ЧеРо", 1997.
[ККЧ+03a] Кудрявцев Л.Д., Кутасов А.Д., Чехлов В.И., Шабунин М.И. Интегралы. Ряды. 2-е изд., ФИЗМАТЛИТ, 2003.
[ККЧ+03b] Кудрявцев Л.Д., Кутасов А.Д., Чехлов В.И., Шабунин М.И. Функции многих переменных. 2-е изд., ФИЗМАТЛИТ, 2003.