What effect would decreasing the distance between objects have on their gravitational attraction to each other?

Will you chech and finish these for me, because i am stumped with them.

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=

What are some important factors to consider when choosing a warm-up before your workout?