Calculating Angular Acceleration w/ Torque & Moment of Inertia

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Torque and moment of inertia are critical for calculating angular acceleration using the formula α = τ/I, where τ is torque and I is moment of inertia. In the example provided, with torque at 12 kg m²/s² and moment of inertia at 3.00 kg m², the resulting angular acceleration is 4 rad/s². The discussion highlights that radians are considered a dimensionless unit, which helps categorize quantities as angular. This distinction is important for clarity in physics calculations involving rotational motion. Understanding these concepts is essential for solving related problems effectively.
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Homework Statement



this is a question just to help with my understanding: ...

when Torque (kg m^2/s^2) and the Moment of Inertia (kg m^2) are known and used to find angular acceleration, ... T(net)/I, are the units for the resulting acceleration rad/s^2

Thanks :-)

Homework Equations


##\tau = I \alpha##

The Attempt at a Solution


[/B] Example:
t = 12 kg m^2/s^2
I = 3.00 kg m^2

angular acceleration = torque/I = 12 kg m^2/s^2 / 3.00 kg m^2 = 4 units(?) / s^2
 
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Yes. Angular acceleration is given in radians per second squared ##(rad/s^2)##.

The radian is sort of a "unitless unit" that appears and disappears as required when working with angular quantities. It's based on a ratio of lengths from the unit circle, where an angle is defined via the arclength along the circle divided by the radius length. It serves to distinguish a quantity as being angular in nature.
 
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thank you! :-)
 
gneill said:
unitless unit
How about "dimensionless unit"?
 
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haruspex said:
How about "dimensionless unit"?
Sure! That's probably better nomenclature. :smile:
 
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The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

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