Why earth magnetism not attract iron

Dao makes a table to identify the variables used in the equations for centripetal acceleration. what quantities belong in cells x and y?

As the distance from a magnet increases, what happens to the magnet force?

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=