Finding Moment of Inertia for a Uniform Thin Solid Door

In summary, the moment of inertia of a uniform thin solid door with height 2.2 m, width .870 m, and mass 23 kg can be found by integrating r^2 dm, where dm is determined by the density and a suitable differential. The bounds of the integral and dm can be determined by the geometry of the problem. Alternatively, the moment of inertia of a uniform rectangular plate can also be used, given by I_{cm} = \frac{1}{12}M(width^2 + height^2). Calculus may be needed to solve this type of problem.
  • #1
jmf322
18
0
Can someone point me in the right direction on how to find the moment of inertia of a uniform thin solid door, height 2.2 m, width .870 m and mass 23 kg. Do I need to use calculus to solve this type of problem? thanks!
 
Physics news on Phys.org
  • #2
moment of inertia = Integrate[r^2 dm] where dm is given by a density * an appropriate differential. r is perpendicular distance from the mass element to the axis of rotation. the bounds of the integral and the dm are given by the geometry of the problem.
 
  • #3
Use the moment of inertia of an uniform rectangular plate

[tex] I_{cm} = \frac{1}{12}M(width^2 + height^2) [/tex]
 
  • #4
sweet thanks guy, i got it! laters
 

1. What is moment of inertia?

Moment of inertia is a physical property of an object that describes how difficult it is to change its rotational motion. It is also known as the rotational inertia of an object.

2. How is moment of inertia calculated?

Moment of inertia is calculated by taking the sum of the mass of each particle multiplied by the square of its distance from the axis of rotation. This can be represented by the equation I = Σmr², where I is the moment of inertia, m is the mass of the particle, and r is the distance from the axis of rotation.

3. What is the unit of moment of inertia?

The unit of moment of inertia is kilogram meter squared (kgm²) in the SI system. In the English system, it is expressed as slug feet squared (slugft²).

4. What factors affect the moment of inertia of an object?

The moment of inertia of an object is affected by its mass distribution and its shape. Objects with a larger mass and/or a more spread out mass distribution will have a higher moment of inertia.

5. How is moment of inertia used in real life applications?

Moment of inertia is used in various fields of engineering, such as structural and mechanical engineering, to determine the stability and strength of structures and machines. It is also used in physics to analyze the motion of rotating objects, such as planets and satellites.

Similar threads

  • Introductory Physics Homework Help
2
Replies
40
Views
2K
Replies
25
Views
431
  • Introductory Physics Homework Help
Replies
2
Views
602
  • Introductory Physics Homework Help
Replies
3
Views
845
  • Introductory Physics Homework Help
Replies
13
Views
1K
  • Introductory Physics Homework Help
Replies
21
Views
1K
  • Introductory Physics Homework Help
Replies
8
Views
7K
  • Introductory Physics Homework Help
Replies
1
Views
2K
  • Introductory Physics Homework Help
Replies
8
Views
1K
  • Introductory Physics Homework Help
Replies
12
Views
935
Back
Top