Intermediate Axis Theorem.... fun to learn it again with You Tube

In summary, a friend of mine shared a YouTube video with me, saying he was sure I would love it. He described it as very strange with a rotating wingnut in the space station flipping over on its rotation axis, over and over, while it spun rapidly. After watching the video, I verified I was taught the intermediate axis theorem in my undergraduate physics mechanics class. Grabbing my ping pong paddle from my basement, I have been entertained by attempting to flip the racquet about the intermediate axis and had fun showing my family.
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CPW
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A friend of mine shared a YouTube video with me, saying he was sure I would love it. He described it as very strange with a rotating wingnut in the space station flipping over on its rotation axis, over and over, while it spun rapidly.

After watching the video, I verified I was taught the intermediate axis theorem in my undergraduate physics mechanics class.

Grabbing my ping pong paddle from my basement, I have been entertained by attempting to flip the racquet about the intermediate axis and had fun showing my family. You might too enjoy this topic.
 
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I learned a bit about these theorems while practicing knife throwing. You throw a knife nearly the same as throwing a baseball or cricket ball; use your hand, arm and wrist to power the flight and your fingers to spin the ball or blade. Balls have spherical symmetry but knives have three distinct rotational axes.

The knife thrower cares primarily about rotation of the longest axis of the knife vertically aligned with direction of flight, rotating at an origin roughly 3cm along the blade measured from the interior end of the haft (handle) for a 20cm knife. This rotation origin corresponds to the knife's center of gravity (cog). The amount of rotation imparted to the knife, measured in 1/2 turns, depends on the distance to the target. When the knife is grasped by the blade, one half turn represents the shortest flight distance to strike point first.

A typical throw covers a distance of 9m (10 yards) in 1.5 turns, ending point first in the target. The throw begins in the hips, travels down the throwing leg and arm, continues with the 'flip' or rotation imparted by the fingers at release as the arm points toward the target, and finishes with a distinct follow through motion of the hand, arm and entire body much like a pitcher.
 
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Here's an application of the theorem from the Le Mans automotive racetrack.

 
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I guess this idea deserves a vid. This clip from wiki shows an overhand axe throw but the same principles apply.
310px-slow_motion_axe_throwing-gif.gif


Axe throwing in slow motion

Notice the rotation along the longest axis for stability in flight and the exaggerated follow through of the entire body
 

1. What is the Intermediate Axis Theorem?

The Intermediate Axis Theorem is a principle in physics that describes the rotation of a rigid body around its intermediate axis. It states that when a rigid body is spinning around its intermediate axis, it is unstable and will tend to wobble or tumble, unless it is rotating fast enough.

2. How does the Intermediate Axis Theorem apply to real-life objects?

The Intermediate Axis Theorem can be observed in many real-life objects, such as tops, frisbees, and satellites. These objects rotate around their intermediate axis and exhibit wobbling or tumbling if they are not spinning fast enough.

3. What is the significance of the Intermediate Axis Theorem?

The Intermediate Axis Theorem is important in understanding the stability and motion of rotating objects. It helps scientists and engineers design and control objects that rotate around their intermediate axis, such as satellites and missiles.

4. Can the Intermediate Axis Theorem be demonstrated visually?

Yes, the Intermediate Axis Theorem can be demonstrated visually through experiments and simulations. There are also many videos on YouTube that show the principle in action, making it a fun and interactive way to learn about it.

5. Are there any real-world applications of the Intermediate Axis Theorem?

Yes, the Intermediate Axis Theorem has many practical applications in fields such as aerospace engineering, robotics, and sports. By understanding this principle, scientists and engineers can design more stable and efficient rotating objects.

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