A nonconducting spherical shell, with an inner radius of 4 cm and an outer radius of 6 cm, has charge spread nonuniformly through its volume between its inner and outer surfaces. The volume charge density is?

Respuesta :

Answer:

[tex]1.57 * 10^{3} Q[/tex]

Explanation:

The volume charge density is defined by ρ = [tex]\frac{Q}{V}[/tex] (Equation A), where Q is the charge and V, the volume.

The units in the S.I. are [tex]\frac{Coulombs}{m^{3} }[/tex], so we have to express the radius in meters:

inner radius = [tex]4 cm * \frac{1 m}{100 cm} = 0.04m[/tex]

outer radius = [tex]6 cm * \frac{1m}{100cm}  = 0.06m[/tex]

Now, we know that the volume of the sphere is calculated by the formula:

[tex]V = \frac{4}{3}\pi r^{3}[/tex], and as we have an spherical shell, the volume is calculated by the difference between the outher and inner spheres:

V = [tex]\frac{4}{3}\pi (r_{o} ^{3} - r_{i} ^{3})[/tex], where [tex]r_{o}[/tex] is the outer radius and [tex]r_{i}[/tex] is the inner radius.

Replacing the volume formula in the Equation A:

ρ = [tex]\frac{Q}{\frac{4}{3}\pi(r^{3} _{o}-r_{i} ^{3})}[/tex]

ρ = [tex]\frac{3Q}{4\pi (r_{o} ^{3}-r_{i} ^{3} ) }[/tex]

Replacing the values of the outer and inner radius whe have:

ρ = [tex]\frac{3Q}{4\pi (1.52 * 10^{-4})}[/tex]

ρ = [tex]1.57 * 10^{3} Q[/tex]