Answer
See explanation.
Work Step by Step
a. As explained in the section on Gauss’s Law, any excess charge is on the outside surface of the car. The occupants inside the car are at the same electric potential as the car itself, 10000 V. The electric potential does not vary from point to point within the car, so no currents flow.
b. If the occupants were to exit the car (don’t do that), the ground is at a potential of 0 volts. Because they are at high potential, much current would flow and the consequences would be serious.
