A light meterstick is loaded with masses of5.0 kg and 3.0 kg
at the 36 cm and89 cm positions, respectively. What is the moment
of inertiaabout an axis through the 0 cm end of the
meterstick?

Respuesta :

Answer:[tex]I=3.024\ kg-m^2[/tex]

Explanation:

Given

mass of first [tex]m_1=5 kg[/tex]

mass of second [tex]m_2=3 kg[/tex]

Distance of [tex]m_1[/tex] from origin [tex]r_1=36 cm[/tex]

Distance of [tex]m_2[/tex] from origin [tex]r_2=89 cm[/tex]

Moment of inertia is given by multiplication of mass and square of distance

[tex]I=\sum mr^2[/tex]

[tex]I=m_1r_1^2+m_2r_2^2[/tex]

[tex]I=5\times 0.36^2+3\times 0.89^2[/tex]

[tex]I=0.648+2.376[/tex]

[tex]I=3.024\ kg-m^2[/tex]

Answer:

[tex]I=4.47\ kg.m^{2}[/tex]

Explanation:

Given:

A light meter stick (assuming mass-less) is loaded with point masses at the following positions.

  • mass of first object, [tex]m_1=5\ kg[/tex]
  • mass of second object, [tex]m_2=3\ kg[/tex]
  • position of the first mass, [tex]x_1=36\ cm=0.36\ m[/tex]
  • position of the second mass, [tex]x_2=89\ cm=0.89\ m[/tex]

As we know that moment of inertia for point mass is given by:

[tex]I=m.R^2[/tex]

where:

[tex]m=[/tex] mass of the object

[tex]R=[/tex] radial distance from the axis of rotation

Now the total moment of inertia:

[tex]I=m_1.x_1^2+m_2.x_2^2[/tex]

[tex]I=5\times 0.36+3\times 0.89[/tex]

[tex]I=4.47\ kg.m^{2}[/tex]