Dust was originally discovered because the stars in certain clusters seemed to be fainter than expected. suppose a star is behind a cloud of dust that dims its brightness by a factor of 100. suppose you do not realize the dust is there. how much in error will your distance estimate be? can you think of any measurement you might make to detect the dust?

Four point charges each having charge q are located at the corners of a square having sides of length a. find symbolic expressions for the following. (a) the total electric potential at the center of the square due to the four charges (use any variable or symbol stated above along with the following as necessary: ke.) vtotal= (b) the work required to bring a fifth charge p from infinity to the center of the square (use any variable or symbol stated above along with the following as necessary: w=