Q1. In a science fiction story, a microscopic black hole is given an enormous positive charge by firing an un-neutralized ion drive exhaust (consisting of positively charged xenon ions) into it for six months. The idea behind the charging process is to be able to confine and manipulate this dangerous object with powerful electric fields. Assume the charge on the black hole is 5740 C. At what distance from it is the electric potential equal to 1100 V?
Q2. An observer moving toward Earth with a speed of 0.97 notices that it takes 5min for a person to fill her car with gas. Assume, instead, that the observer had been moving away from Earth with a speed of 0.80c. How much time would observer have measured for the car to be filled in this case?