24. Electric Force & Field; Gauss' Law

A cube has sides equal to $4.0\mathrm{cm}$. The net flux through the cube is $12\mathrm{N}·{\mathrm{m}}^2/\mathrm{C}$ outward. Is the net charge in the cube positive, negative or zero?

An electric field with strength $3500\mathrm{N}/\mathrm{C}$ exists just outside a face of a large block of aluminum. If the electric field points towards the block, what is the surface charge density on the face of the block?

A charged paint is spread in a very thin uniform layer over the surface of a plastic sphere of diameter 12.0 cm, giving it a charge of −49.0 μ C. Find the electric field (b) just outside the paint layer;

A charged paint is spread in a very thin uniform layer over the surface of a plastic sphere of diameter 12.0 cm, giving it a charge of −49.0 μ C. Find the electric field (a) just inside the paint layer;

The nuclei of large atoms, such as uranium, with 92 protons, can be modeled as spherically symmetric spheres of charge. The radius of the uranium nucleus is approximately 7.4×10−15 m. (c) The electrons can be modeled as forming a uniform shell of negative charge. What net electric field do they produce at the location of the nucleus?

The nuclei of large atoms, such as uranium, with 92 protons, can be modeled as spherically symmetric spheres of charge. The radius of the uranium nucleus is approximately 7.4×10−15 m. (b) What magnitude of electric field does it produce at the distance of the electrons, which is about 1.0×10−10 m?