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**1. Homework Statement**

A solid non-conducting sphere of radius R = 1.12m.

The sphere posses a total charge Qtot spread uniformally throughout its volume.

a) derive equations for electric field for

1) 0<r<R

2) r>R

result in terms of r R and Q

b) Derive an equation that gives the work needed for you to bring a point charge "q" from infinitely far away to inside the sphere at r = R/2

Answer is W = 11/8 (kQ/R) q

**2. Homework Equations**

for 0<r<R

E1 = KQR/r^3

for r>R

E2 = KQ/R^2

**3. The Attempt at a Solution**

q∫KQR/r^3 + q∫KQ/R^2