Car a leaves town heading east with a constant speed of 20 miles/hr. an hour later car b leaves town heading east as well, with a constant speed of 25 miles/hr. how long after car b leaves will it intercept car a?

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=