What Is the Moment of Inertia About a Point One-Fourth the Length from One End?

AI Thread Summary
The discussion centers on calculating the moment of inertia of a system of small blocks clamped to a rod, specifically about an axis located one-fourth the length from one end. Participants emphasize the importance of visualizing the problem by drawing a diagram to clarify the axis's position. The axis is described as being one-fourth of the way from one end, which is halfway between that end and the center of the rod. The original poster resolves their confusion before receiving further assistance. Clear communication and visual aids are highlighted as effective strategies for understanding physics problems.
K.QMUL
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Homework Statement



Small blocks, each with mass m, are clamped at the ends and at the center of a rod of length L and negligible mass

Compute the moment of inertia of the system about an axis perpendicular to the rod and passing through a point one-fourth of the length from one end.

Homework Equations



I = Mr2

What I am having difficulty with

I don't understand where this axis is, it would help if someone would explain or better draw a diagram to help me understand.
 
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K.QMUL said:
I don't understand where this axis is, it would help if someone would explain or better draw a diagram to help me understand.
Did you try drawing a diagram for yourself? The directions seem pretty straightforward.

Draw a line representing the rod. Now draw a line perpendicular to it. If it that perpendicular line were in the middle of the rod, it would be 1/2 the length from one end. Move it so that it's 1/4 the length from one end.
 
Do you agree that one-fourth of the rod length, as measured from one end, must be midway between that end and the center point?
 
Sorry, i figured it out before everyones reply, so I am all good. Thanks for the help though
 

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