Calculating Moment of Inertia for a Curved Rod with Respect to a Specific Axis

In summary, we are given a thin, homogeneous, curved rod with a radius of curvature 𝑅 and mass π‘š. We need to find the moment of inertia 𝐼π‘₯β€²π‘₯ β€² with respect to the π‘₯β€²- axis passing through the center of mass 𝐺. Using Steiners sats, we can find 𝐼π‘₯π‘₯ based on 𝐼π‘₯β€²π‘₯β€² and the distance of 𝐺 from the π‘₯β€² axis. However, it may be easier to calculate 𝐼π‘₯π‘₯ and then shift it to the required π‘₯β€² axis using the parallel and perpendicular axis the
  • #1
Iqish
8
1
Homework Statement
A thin, homogeneous, curved rod with
the radius of curvature 𝑅 and mass π‘š are in
π‘₯𝑦 plane. Determine the moment of inertia,
𝐼π‘₯'π‘₯ ', with respect to the π‘₯ 'axis, which goes
through the body's center of mass G
Relevant Equations
Steiners sats:𝐼π‘₯π‘₯ = 𝐼π‘₯β€²π‘₯β€² + π‘šπ‘¦^2𝐺
Given:Thin, homogeneous, curved rod with radius of curvature 𝑅 See figure to the down.
7m2HF.png

Find: The moment of inertia 𝐼π‘₯β€²π‘₯ β€² with respect to π‘₯β€²- the axis passing through the center of mass (point 𝐺).
Can someone who can help me ?
 
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  • #2
Iqish said:
Homework Statement:: A thin, homogeneous, curved rod with
the radius of curvature 𝑅 and mass π‘š are in
π‘₯𝑦 plane. Determine the moment of inertia,
𝐼π‘₯'π‘₯ ', with respect to the π‘₯ 'axis, which goes
through the body's center of mass G
Relevant Equations:: Steiners sats:𝐼π‘₯π‘₯ = 𝐼π‘₯β€²π‘₯β€² + π‘šπ‘¦^2𝐺

Given:Thin, homogeneous, curved rod with radius of curvature 𝑅 See figure to the down.
View attachment 258878
Find: The moment of inertia 𝐼π‘₯β€²π‘₯ β€² with respect to π‘₯β€²- the axis passing through the center of mass (point 𝐺).
Can someone who can help me ?

Have you learned about the parallel and perpendicular axis theorems?

Just an initial thought that I have on this. So it looks quite difficult to actually calculate the moment of inertia about the required axis, so it suggests to me that we will be shifting it to that axis (via parallel axis theorem). Perhaps, we can find [itex] I_{Oz} [/itex] (out of the page) , turn that into [itex] I_{x} [/itex] via perpendicular axis theorem and then shift it to the required axis (would require us to know the location of G, but that seems easier to find than calculating about that axis. Otherwise, maybe we find [itex] I_{x} [/itex] and then shift?

(Note, we would be 'reverse' shifting it as the parallel axis theorem is defined for an axis relative to centroid axis, would just mean that we subtract the [itex] m d^2 [/itex], rather than add it)
 

1. What is the moment of inertia?

The moment of inertia is a measure of an object's resistance to changes in its rotational motion. It is similar to mass in linear motion, but for rotational motion.

2. How do you calculate the moment of inertia?

The moment of inertia can be calculated by multiplying the mass of an object by the square of its distance from the axis of rotation. The formula is I = mr^2, where I is the moment of inertia, m is the mass, and r is the distance from the axis of rotation.

3. What is the significance of the moment of inertia?

The moment of inertia is important in understanding an object's rotational behavior. It determines how much torque is needed to accelerate or decelerate an object in rotational motion.

4. How does the moment of inertia differ for different shapes?

The moment of inertia varies for different shapes and depends on the distribution of mass around the axis of rotation. Objects with most of their mass concentrated near the axis of rotation have a smaller moment of inertia compared to objects with their mass spread out further from the axis.

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

The moment of inertia is used in various real-life applications such as designing machines and structures, calculating the stability of rotating objects, and predicting the behavior of objects in rotational motion.

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