2. A solid sphere of radius a is concentric with a hollow sphere of radius b, where b>a.

The solid sphere has a charge -3Q and the hollow sphere has a charge of +2Q.

Find the electric field at r:

(a) For a

(b) For r>b.

3. In a certain crystal, Cl^- atoms form the 4 corners of a triangular pyramid, separated from one another by 50nm. Find the electric field in the middle of the pyramid if the Cl atom at the top is not Cl^-, but Cl. (it has lost an electron)

4. Use Gauss' Law to find the electric field of the following charge distributions and answer the following questions. Give the electric field for all regions of space.

(a) a point charge

(b) a solid sphere of uniform charge density

(c) a hollow sphere with uniform charge density

(d) a line of charge

(e) an infinite sheet of charge

(f) a conducting surface

(g) compare the electric fields of a point charge, a line charge, and a sheet of charge, and discuss their behavior

5. What would be the electrical field required to keep an electron in a stable circular orbit in a Hydrogen atom in the Bohr model?

6. A small sphere is placed midway between the plates of a parallel plate capacitor. (separation distance between the plates is 40 cm, negative plate on the bottom)

(a) Sketch the electric field lines between the plates.

(b) If the plates are maintained at -50kV, what is the magnitude of the electric field between the plates?

(c) If the sphere has a mass of 3 grams, what must be the charge of the sphere for it to remain stationary in the middle?

(d) How many electrons would correspond to your answer in (c)?

7. A muon is decelerated by an electric field of 7.2 x 10³ N/C to rest over a distance of 4.00cm.

(a) Find the particle's initial velocity and kinetic energy.

(b) Perform the same calculations in (a) for a tau particle