Class: Pulo::MomentOfInertia

Inherits:
Object
  • Object
show all
Defined in:
lib/pulo/machine/mechanics/moments_of_inertia.rb

Class Method Summary collapse

Class Method Details

.cone(mass, radius, height) ⇒ Object 



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# File 'lib/pulo/machine/mechanics/moments_of_inertia.rb', line 52

def self.cone(mass, radius, height)
  (radius**2+4*height**2)*(3*mass/20)
end

.cuboid(mass, width, height) ⇒ Object

cuboid or plate of arbitrary depth (in direction of axis of rotation)



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# File 'lib/pulo/machine/mechanics/moments_of_inertia.rb', line 57

def self.cuboid(mass, width, height)
  (height**2+width**2)*(mass/12)
end

.cylinder(mass, radius, height) ⇒ Object 



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# File 'lib/pulo/machine/mechanics/moments_of_inertia.rb', line 32

def self.cylinder(mass, radius, height)
  (3*radius**2+height**2)*mass/12.0
end

.cylindrical_shell(mass, radius) ⇒ Object

cylindrical shell on its axis



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# File 'lib/pulo/machine/mechanics/moments_of_inertia.rb', line 28

def self.cylindrical_shell(mass, radius)
  (mass*radius**2)
end

.disc(mass, radius) ⇒ Object

disc



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# File 'lib/pulo/machine/mechanics/moments_of_inertia.rb', line 23

def self.disc(mass, radius)
  (mass*radius**2)/4.0
end

.hoop(mass, radius) ⇒ Object

hoop



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# File 'lib/pulo/machine/mechanics/moments_of_inertia.rb', line 18

def self.hoop(mass, radius)
  (mass*radius**2)/2.0
end

.point_mass(mass, distance) ⇒ Object 



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# File 'lib/pulo/machine/mechanics/moments_of_inertia.rb', line 3

def self.point_mass(mass, distance)
  mass*distance**2
end

.rod(mass, length) ⇒ Object

rod around its mid point



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# File 'lib/pulo/machine/mechanics/moments_of_inertia.rb', line 8

def self.rod(mass, length)
  (mass*distance**2)/12.0
end

.rod_end(mass, length) ⇒ Object

rod around its mid point



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# File 'lib/pulo/machine/mechanics/moments_of_inertia.rb', line 13

def self.rod_end(mass, length)
  (mass*length**2)/3.0
end

.sphere(mass, radius) ⇒ Object 



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# File 'lib/pulo/machine/mechanics/moments_of_inertia.rb', line 44

def self.sphere(mass, radius)
  (2*mass*radius**2)/5.0
end

.spherical_shell(mass, radius) ⇒ Object 



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# File 'lib/pulo/machine/mechanics/moments_of_inertia.rb', line 40

def self.spherical_shell(mass, radius)
  (2*mass*radius**2)/3.0
end

.thick_spherical_shell(mass, inner_radius, outer_radius) ⇒ Object 



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# File 'lib/pulo/machine/mechanics/moments_of_inertia.rb', line 48

def self.thick_spherical_shell(mass, inner_radius,outer_radius)
  ((outer_radius**5-inner_radius**5)/(outer_radius**3-inner_radius**3))*(2*mass/5)
end

.tube(mass, inner_radius, outer_radius) ⇒ Object 



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# File 'lib/pulo/machine/mechanics/moments_of_inertia.rb', line 36

def self.tube(mass, inner_radius,outer_radius)
  (inner_radius**2+outer_radius**2)*mass/2.0
end