Answer:
<em>The kinetic energy of a spinning disk will be reduced to a tenth of its initial kinetic energy if its moment of inertia is made five times larger, but its angular speed is made five times smaller.</em>
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Explanation:
Let us first consider the initial characteristics of the angular motion of the disk
moment of inertia = ![I](https://tex.z-dn.net/?f=I)
angular speed = ω
For the second case, we consider the characteristics to now be
moment of inertia =
(five times larger)
angular speed = ω/5 (five times smaller)
Recall that the kinetic energy of a spinning body is given as
![KE = \frac{1}{2}Iw^{2}](https://tex.z-dn.net/?f=KE%20%3D%20%5Cfrac%7B1%7D%7B2%7DIw%5E%7B2%7D)
therefore,
for the first case, the K.E. is given as
![KE = \frac{1}{2}Iw^{2}](https://tex.z-dn.net/?f=KE%20%3D%20%5Cfrac%7B1%7D%7B2%7DIw%5E%7B2%7D)
and for the second case, the K.E. is given as
![KE = \frac{1}{2}(5I)(\frac{w}{5} )^{2} = \frac{5}{50}Iw^{2}](https://tex.z-dn.net/?f=KE%20%3D%20%5Cfrac%7B1%7D%7B2%7D%285I%29%28%5Cfrac%7Bw%7D%7B5%7D%20%29%5E%7B2%7D%20%20%20%3D%20%5Cfrac%7B5%7D%7B50%7DIw%5E%7B2%7D)
![KE = \frac{1}{10}Iw^{2}](https://tex.z-dn.net/?f=KE%20%3D%20%5Cfrac%7B1%7D%7B10%7DIw%5E%7B2%7D)
<em>this is one-tenth the kinetic energy before its spinning characteristics were changed.</em>
<em>This implies that the kinetic energy of the spinning disk will be reduced to a tenth of its initial kinetic energy if its moment of inertia is made five times larger, but its angular speed is made five times smaller.</em>
Positive. The 1st object loses electrons and will thus have an imbalance of charge with loss of electrons.