Rotational Kinetic Energy - Clarification on what I need to solve for

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SUMMARY

The discussion focuses on calculating the rotational kinetic energy (KE) of a solid cylinder wheel with a mass of 13 kg and a radius of 0.33 m, which experiences an angular acceleration of 5 rad/s² for 18 seconds. The user initially calculated the total kinetic energy using the formula KE = 1/2mv² + 1/2 Iω², resulting in a total KE of 5765.438 J, with the rotational component being 31.85 J. The user clarified that the problem specifies no translation, indicating that only the rotational kinetic energy should be calculated, leading to a focus on the correct application of the formula 1/2 Iω².

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grandprix
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Homework Statement


A wheel (solid cylinder), mass of 13 kg and radius of 0.33m is initially at rest. The wheel undergoes an angular acceleration of 5 rad/s^2 for 18 seconds, rotating about its center axis (no translation). Find the Kinetic energy of the wheel at the end of the 1 seconds.

Homework Equations


KE = 1/2mv^2 + 1/2 I*w^2


The Attempt at a Solution


Okay so I was a little confused on whether I am finding the Total KE, or just th rotational KE.

If I were solving for total, KE = 1/2mv^2 + 1/2 I*w^2
First I need to solve for v, which I got to be 29.7, by employing the formula v=wr

I solved the equation for total KE and got 5765.438, where 5733.58 = 1/2mv^2 and 31.85 = is equal to 1/2 I W^2.

If I just needed to find the KE rot, then the answer would be 31.85.
 
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grandprix said:

Homework Statement


A wheel (solid cylinder), mass of 13 kg and radius of 0.33m is initially at rest. The wheel undergoes an angular acceleration of 5 rad/s^2 for 18 seconds, rotating about its center axis (no translation). Find the Kinetic energy of the wheel at the end of the 1 seconds
The question does say no translation, so I assume you just need to get the rotational kinetic energy.

EDIT: How did you get so little rotational kinetic energy? Did you apply 1/2Iw2 correctly?
 
Thank you ! I may have done that wrong. I will chck it over
 

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