Find the electric field E⃗ (r⃗ )E→(r→)E_vec(r_vec) inside the sphere (for rrr< aaa) in terms of the position vector r⃗ r→r_vec. Express your answer in terms of r⃗ r→r_vec, rhorhorho (Greek letter rho), and ϵ0ϵ0epsilon_0.

Solution :

Using the Gauss law, the electric field intensity of a sphere is given by :

Now the enclosed charge inside the sphere (r<a) is

Hence, the electric field intensity becomes as follows :

Thus, the electric field inside the sphere is given by :

pe = weightxheight = 2000x1000=2,000,000joules

the tires are rotating at 0.434 rpmlinear speed=45 m/sdiameter=0.550 mradius=0.275 mnow v= rωω= v/rω=45/0.275ω=163.6 rad/sω=163.6 rad/s (1rev/2π rad) (60s/1m)ω=1563 rpm