There seems to be some confusion over the axes. They must mean Iy.whitejac said:
A moment is a measure of the tendency of an object to rotate about a fixed point. It is related to inertia because the greater the moment of an object, the harder it is to change its rotational motion, which is a property of inertia.
Understanding moments and inertia is important in order to analyze and predict the motion of objects, especially in rotational systems. It is also crucial in engineering and design, as it helps in the proper distribution of weight and forces in structures.
The formula for calculating moments is M = F x d, where M is the moment, F is the force applied, and d is the distance from the fixed point. The formula for calculating inertia is I = m x r^2, where I is the moment of inertia, m is the mass of the object, and r is the distance from the axis of rotation.
A common example of a moment and inertia in real life is a seesaw. The further away a person sits from the center, the greater their moment and the harder it is to change the rotational motion. Inertia can also be observed when trying to spin a heavy object, such as a bowling ball, compared to a lighter one, such as a tennis ball.
In machines, moments and inertia can be used to optimize the design and reduce friction. By understanding the moments and inertia of different parts, engineers can distribute weight and forces in a way that minimizes the effort needed to move the machine, leading to increased efficiency and performance.