A 90kg person pushes a 25kg cart 15m up a ramp using a force of 80N. The top of the ramp is 3m above ground. It takes 8 seconds to go from bottom to top.

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=