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## Homework Statement

You are a project manager for a manufacturing company. One of the machine parts on the assembly line is a thin, uniform rod that is

60.0 cm long and has mass 0.700 kg .

1What is the moment of inertia of this rod for an axis at its center, perpendicular to the rod?

Express your answer with the appropriate units.

2One of your engineers has proposed to reduce the moment of inertia by bending the rod at its center into a V-shape, with a

60.0∘ angle at its vertex. What would be the moment of inertia of this bent rod about an axis perpendicular to the plane of the V at its vertex?

## Homework Equations

I of rod = 1/12 * m *L

^{2}

I of rod aorund end 1/3 * m * L

^{2}

## The Attempt at a Solution

mass= .7

length= 60 cm = .6 m

Ok, I got part 1 it is .021

for part 2

If the rod is bent into a v shape and rotated around its axis, it is 2 rods half the length of the original rotation around their ends so the moment of Inertia should be

1/3 * .7 * .3^2 + 1/3 * .7 * .3^2

= .2716

why is this wrong?

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