The work required to raise an object to a height is equal to the gravitational potential energy the object gains. <em>(C)</em>
Sodium weights 0.968 so the density is equal to 968
Answer:
E = ![\frac{1}{4\pi \epsilon_o } \ r^2](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B4%5Cpi%20%20%5Cepsilon_o%20%7D%20%5C%20%20r%5E2)
Explanation:
For this exercise let's use Gauss's law. The Gaussian surface that follows the symmetry of the charges is a sphere
Ф = ∫ E. dA =
the bold are vectors, the radii of the sphere and the electric field are parallel therefore the scalar product reduces to the algebraic product
Ф = ∫ E dA = \frac{x_{int} }{\epsilon_o}
E ∫ dA = \frac{x_{int} }{\epsilon_o}
E A = \frac{x_{int} }{\epsilon_o}
the area of a sphere is
A = 4π r²
the charge inside the sphere is q = + q
we substitute
E 4π r² = \frac{x }{\epsilon_o}
E = ![\frac{1}{4\pi \epsilon_o } \ r^2](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B4%5Cpi%20%20%5Cepsilon_o%20%7D%20%5C%20%20r%5E2)