Question1
On a humid day, the electric field of 2.00×10^4 N/C is enough to produce sparks about an inch long. Assume that in the physics class, a Van de Graaff generator with a sphere radius of 15.0 cm is producing sparks 6 inches long.
a) Use Gauss's law to compute amount of charge stored on the surface of the sphere sooner than bravely discharge it with the hand.
b) Suppose all charge is concentrated at the center of the sphere, and use Coulomb's law to compute the electric field at the surface of the sphere
Question2
An electron with kinetic energy of 4.0 x 10-16 J is moving to the right along the axis of a cathode-ray tube.
1. There is an electric field = (3.0 x 104 N/C) in the region between the deflection plates. Everywhere as well, = 0.
2. At what angle is an electron moving with respect to the axis? (Positive angle measured counter clockwise with respect to the axis)
3. At what distance from the axis will an electron strike the fluorescent screen?