The ratio of moment of inertia of a circular plate to that of a square...
Concept:
Moment of inertia of circular plate,
Moment of inertia of Square plate,
Calculation:
The ratio of the moment of inertia of a circular plate to that of a square plate is, Which is less than 1.
Important Points
The following table shows the Second moment of inertia of different shapes
The ratio of moment of inertia of a circular plate to that of a square...
The moment of inertia is a property of an object that measures its resistance to rotational motion. It depends on the mass distribution of the object and the axis of rotation. For a circular plate and a square plate of equal depth, the mass is distributed differently, leading to different moment of inertia values.
The moment of inertia of a circular plate is given by the formula:
I_circular = (1/4) * m * r^2
where m is the mass of the plate and r is the radius of the plate.
The moment of inertia of a square plate is given by the formula:
I_square = (1/12) * m * h^2
where m is the mass of the plate and h is the side length of the square plate.
To compare the two moment of inertia values, we can take the ratio of I_circular to I_square:
I_circular / I_square = [(1/4) * m * r^2] / [(1/12) * m * h^2]
The mass cancels out in the ratio, so we are left with:
I_circular / I_square = (r^2) / (3 * h^2)
From the equation, we can see that the ratio of the moment of inertia of a circular plate to that of a square plate depends on the ratio of r^2 to h^2.
Now, let's consider a circular plate and a square plate with equal depth. This means that the height of the square plate is equal to the diameter of the circular plate (h = 2r). Substituting this into the ratio equation:
I_circular / I_square = (r^2) / (3 * (2r)^2) = (r^2) / (12r^2) = 1/12
So, the ratio of moment of inertia of a circular plate to that of a square plate for equal depth is 1/12, which is less than one. Therefore, the correct answer is option A: less than one.