Which of the following explains why parallax is used to measure stars? It takes into consideration the changing brightness of stars.
It provides greater accuracy for measuring stars near the earth.
It takes into consideration the changing position of stars.
It provides greater accuracy for measuring stars far from the earth.

Plss anybody know how to do this? ? i need the answers from a through d

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.

How does an observation about an object differ from an inference about that object