The moment of inertia of a thin uniform rod of
mass M and length L about an axis
perpendicular to the rod, through its centre is
L. The moment of inertia of the rod about an axis
perpendicular to rod through its end point is
Answers
Answer:
Moment of Inertia, I = ML²/3
Explanation:
Given:-
Rod type = uniform
Mass = M
Length = L
Angle about which it rotates on axis = 90°
Since, its not a point mass object but a rod whose mass m is spread uniformly over the length L. So, in order to find the moment of inertia, we take small change in distance and mass. As:
After distance x, we have: dx & dm
[Refer to the attached image to visualize the scenario]
Using differentiation & integration, we find the value of moment of inertia now.
We know that, by formula:
Density, λ = M/L _______(1)
i.e density equals mass per unit length.
We take small changes in distance and mass as:
dI = dmx² [since, I = mx²]
dI = x² [M/L dx]
∫dI = M/L ∫x²dx
I = M/L [x³/3]
lim ⇒ 0 to L.
I = M/L × L³/ 3
I = ML²/3
Hence, the moment of inertia of the rod about an axis perpendicular to rod through its end point is ML²/3.
Hope it helps! ;-))