X-rays cannot pass through earth's atmosphere. which of these is the best location to place a telescope used to observe x-rays from stars?

mountain
top of building
space
high-flying aircraft

Along the line connecting the two charges, at what distance from the charge q1 is the total electric field from the two charges zero? express your answer in terms of some or all of the variables s, q1, q2 and k =14ï€ïµ0. if your answer is difficult to enter, consider simplifying it, as it can be made relatively simple with some work.