Answer:
Explanation:
Given
![\omega =13-\frac{1}{2}\cdot t^2](https://tex.z-dn.net/?f=%5Comega%20%3D13-%5Cfrac%7B1%7D%7B2%7D%5Ccdot%20t%5E2)
Motor reverse its direction when \omega =0
![13-0.5t^2=0](https://tex.z-dn.net/?f=13-0.5t%5E2%3D0)
![26=t^2](https://tex.z-dn.net/?f=26%3Dt%5E2)
![t=\sqrt{26}=5.099\approx 5.1 s](https://tex.z-dn.net/?f=t%3D%5Csqrt%7B26%7D%3D5.099%5Capprox%205.1%20s)
(b)
![\frac{\mathrm{d} \theta }{\mathrm{d} t}=\omega](https://tex.z-dn.net/?f=%5Cfrac%7B%5Cmathrm%7Bd%7D%20%5Ctheta%20%7D%7B%5Cmathrm%7Bd%7D%20t%7D%3D%5Comega%20)
![\int d\theta =\int_{0}^{5.1}\omega dt](https://tex.z-dn.net/?f=%5Cint%20d%5Ctheta%20%3D%5Cint_%7B0%7D%5E%7B5.1%7D%5Comega%20dt)
![\int d\theta =\int_{0}^{t}(13-.05t^2)dt](https://tex.z-dn.net/?f=%5Cint%20d%5Ctheta%20%3D%5Cint_%7B0%7D%5E%7Bt%7D%2813-.05t%5E2%29dt)
![\theta =(13t-0.1667\times t^3)_0^{5.1}](https://tex.z-dn.net/?f=%5Ctheta%20%3D%2813t-0.1667%5Ctimes%20t%5E3%29_0%5E%7B5.1%7D)
![\theta =44.192^{\circ}](https://tex.z-dn.net/?f=%5Ctheta%20%3D44.192%5E%7B%5Ccirc%7D)
The inner planets are not colder or larger than the outer ones,
and they're not comprised of gas.
The inner planets are the ones that are made of rock. ( D ).
<h3>Answer;</h3>
- <em>The spheres develop opposite charges.
</em>
- <em>Electrons move from Sphere A to Sphere B.
</em>
- <em>The spheres are charged through induction.</em>
<h3><u>Explanation;</u></h3>
- <u><em>When a negatively charged rod is placed near two neutral metal spheres, the spheres will develop opposite charges, because the neutral metal spheres have both negative and positive charges. </em></u>From the basic law of electrostatics unlike charges attracts and like charges repel.
- Thus, <em><u>the sphere will develop opposite charges, electrons will move from Sphere A to sphere B,</u></em> hence we say that the spheres will be charged by induction such that sphere A will acquire a positive charge while sphere B will acquire negative charge.