Mass, centre of mass and moments of material curves and surfaces
[67/79%]Find the static moment and moment of inertia of a semicircular arc of radius with respect to the diameter through its two endpoints.
Find the coordinates of the centroid of the circular arc: , ().
Find the coordinates of the centroid of the arc from the point to the point on the logarithmic spiral
As the point moves, what curve does the point trace out?
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Prove that the static moment of the arc of a parabola relative to the axis of the parabola equals , where and are the radii of curvature of the parabola at its vertex and at the points and respectively.
Find the coordinates and of the centroid of the curve:
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Prove that if a homogeneous curve has an axis of symmetry, then the centroid of the curve lies on that axis.
Prove that the static moment of a curve relative to the axis passing through its centroid equals zero.
Find the moment of inertia of a segment of length relative to an axis lying in the same plane with it and not crossing this segment, if the distance to the axis from one end of the segment equals , and from the other .
Find the moment of inertia of the curve:
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Find the moments of inertia and of one arch of the cycloid
Prove that the point of the plane, defined for a curve or figure by the formulas
(i.e. the centroid), does not depend on the choice of coordinate system.
A right circular cone has height and base radius . Find the distance to the base of the cone from the centroid:
its lateral surface;
its total surface (assuming they are homogeneous).
The base radii of a right frustum of a cone equal and , the angle between the generator and the base equals . Find the centroid of its:
the lateral surface;
the total surface.
Find the centroid of the shell that is:
a spherical zone of height ;
a segment with base radius and height , cut off from a paraboloid of revolution by a plane perpendicular to its axis.
Find the centroid of the part of the surface of a cylinder lying between the planes and , if the cylinder is given by the equation:
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Find the moment of inertia:
the lateral surface of a cylinder with radius and height , relative to its axis;
the lateral surface of a cone with height and base radius , relative to its axis;
a sphere of radius , relative to its diameter.
Find the mass, distributed with linear density along the arc of the plane curve , if:
— the segment ;
— the segment ;
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Find the mass of the entire curve , with linear density .
Find the mass, distributed with linear density , along the plane curve :
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Find the mass, distributed with linear density , along the space curve :
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— the arc of the curve with initial point and terminal point ;
— the arc of the curve , with initial point and terminal point ;
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Find the coordinates of the center of mass, distributed along the plane curve with linear density :
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— the arc of the circle ;
— the cardioid ;
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Find the coordinates of the center of mass, distributed with linear density , along the arc of the helix , if:
const;
, take .
Find the coordinates of the center of mass of the homogeneous curve
Find the coordinates of the center of mass of the homogeneous edge of the surface .
Let the piecewise smooth curve be the union of smooth curves , with masses and position vectors of the centers of mass . Let be the mass of , the center of mass of . Prove that
Find the moment of inertia of the circle .
Find the moment of inertia of the circle .
Find the moments of inertia and of a single arch of the cycloid
Find the moments of inertia of a single turn of the helix
Find the moment of inertia of the circle .
Find the polar moment of inertia of the homogeneous plane curve with respect to the origin, if:
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Determine the mass distributed:
over the surface of the cube with surface density ;
over the sphere with density: а) , б) ;
over part of the elliptic paraboloid with density ;
over part of the hyperbolic paraboloid , cut out by the cylinder , with density const.
Determine the static moment relative to the plane of a homogeneous ( const surface:
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Determine the applicate (z-coordinate) of the center of mass of the hemisphere with surface density:
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Determine the coordinates of the center of mass of homogeneous surfaces:
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Calculate the moments of inertia relative to the coordinate planes of a homogeneous ( const surface:
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Calculate the moment of inertia of a homogeneous ( const) surface:
, relative to the axis ;
, relative to the line , .
Determine the electric charge distributed with density over the surface:
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